The periodic table:

• In 1869, a Russian scientist named Dimitri Mendeleev created a chart of all the known elements. He called it the periodic table.
• At that time, there were only 59 elements known. But Mendeleev thought there must be more elements that had not been discovered yet.
• He left 33 empty spaces in his table for these undiscovered elements.
• Mendeleev gave these undiscovered elements names like “ekasilicon,” “ekaaluminum,” and “ekaboron.” These names meant “one like silicon,” “one like aluminum,” and “one like boron.”
• By 1939, all of Mendeleev’s empty spaces had been filled in. The last element to be discovered was “ekacesium,” which is now called francium.

Transuranic elements:

• Today, there are 118 known elements.
• 92 of these elements are found in nature.
• 26 of these elements are man-made.
• The man-made elements are called transuranic elements.
• Neptunium (Element 93) was the first transuranic element to be discovered. It was discovered in 1940. After the discovery of wrencium (Lr) in 1961, scientists found more new elements. Here are some of them:

1. Rutherfordium (Rf) with atomic number 104.
2. Darmstadtium (Ds) with atomic number 110.
3. Dubnium (Db) with atomic number 105.
4. Roentgenium (Rg) with atomic number 111.
5. Seaborgium (Sg) with atomic number 106.
6. Copernicium (Cr) with atomic number 112.
7. Bohrium (Bh) with atomic number 107.
8. Flerovium (Fl) with atomic number 114.
9. Hassium (Hs) with atomic number 108.
10. Livermorium (Lv) with atomic number 116.
11. Meitnerium (Mt) with atomic number 109.

There are four more elements that scientists think they have found, but they need to do more tests to be sure. These elements are called Ununtrium (Element 113), Ununpentium (Element 115), Ununseptium (Element 117), and Ununoctium (Element 118).

In 2003, Russian scientists said they had found element 115, but other scientists didn’t believe them. They wanted the Russian scientists to do more tests to prove that they had really found the element. The Helmholtz Center did more tests, and now other scientists are reviewing their work.

The International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) are working on adding a new element to the periodic table.

• They have already approved the names for elements 116 (livermorium), 117 (ununseptium), and 118 (ununoctium), but they haven’t decided on permanent names for the last two yet.
• Ununoctium has a very short half-life of only 0.89 milliseconds.

Elements are divided into two main groups: metals and non-metals.

• Metals are elements like lead, gold, and mercury.
• Non-metals are elements like chlorine, bromine, and carbon.
• Some elements, like boron, silicon, germanium, and antimony, can act like both metals and non-metals. These elements are called metalloids.
• There are also elements that are neither metals nor non-metals. These elements are called noble gases. Helium, argon, neon, krypton, radon, and xenon are noble gases that are found in the atmosphere.

Metals

• Elements can be divided into two groups: metals and non-metals. Most of the elements (about 80%) are metals.
• Metals are hard, shiny, and can be easily stretched or hammered into different shapes. They also conduct heat and electricity well. All metals are solid at room temperature, except for mercury and gallium, which are liquid. Metals have high melting and boiling points.

Chemical Properties of Metals

• Metals tend to lose electrons when they react with other substances. When they react with acids, they usually replace the hydrogen in the acid. However, copper, silver, and gold are exceptions to this rule.
• Metal chlorides are true salts, and metal oxides are usually basic. Metal hydrides are ionic, unstable, and reactive.
• All metals are reactive, meaning they can react with common substances like oxygen (in the air), hydrogen, halogens, sulfur, water, and acids. However, the extent to which they react varies.

Metals and Their Reactions

Each metal reacts differently to its surroundings.

Free Metals

Only gold, platinum, and silver are not affected by air and water under normal conditions. These metals are known as free metals.

Minerals and Ores

Various compounds of metals, called minerals, are found in nature. These minerals can be mined.

The mineral from which metal can be economically extracted is called ore.

Metallurgy

The process of extracting metals from their ores is called metallurgy. Metallurgy involves several steps:

Calcination: The concentrated ore is heated in the absence of air.

Roasting: The ore is heated in excess air.

Smelting: The roasted ore is mixed with coke and heated in a furnace to obtain free metal.

Steel and Iron

Steel is a form of iron. To make steel from iron, the carbon content is reduced from 5% to 0.5-1.5%.

Heat Treatment of Steel

Quenching: If steel is heated to bright redness and then suddenly cooled in water or oil, it becomes extraordinarily hard and brittle.

Tempering: By controlled heating and cooling, the hardness and brittleness of quenched steel can be reduced, making it stronger and more durable.

Annealing:

• Heating quenched steel to a temperature between 250-325 degrees Celsius can remove its brittleness without affecting its hardness.
• This process is called annealing, and it involves heating the steel to a temperature below red hot and then cooling it, making it softer.

Rusting of Iron:

• Most metals are found in nature in a combined form and must be extracted from their ores.
• When these metals are exposed to the air, they tend to return to their original form through a process called corrosion.
• In the case of iron, this process is known as rusting.
• Rusting involves the formation of hydrated ferric oxide, and it requires both water and oxygen to occur. Without water or an electrolyte, rusting cannot happen.
• During rusting, hydrogen and oxygen elements are added to the iron, causing its mass to increase.
• Rusting can be prevented by coating the surface of iron with metals or non-metals, or by alloying it with other metals.

Electroplating and Hot Dipping

Electroplating is a process where a metal coating is applied to a surface using an electric current. Nickel and chromium are commonly used for electroplating.

Hot dipping is a process where a metal coating is applied to a surface by dipping it into a molten metal bath. When zinc is applied to iron using hot dipping, it is called galvanizing.

Non-metals

Non-metals are elements that tend to gain electrons to form negative ions called anions. They are usually found as powders or gases, except for bromine, which is a liquid at room temperature.

Non-metals are not shiny and do not conduct heat or electricity well. They cannot be flattened into sheets or stretched into wires like metals. They also have lower melting points than metals.

Alloys

Alloys are mixtures of two or more metals or non-metals. They are often more useful than the individual elements they are made of. Here are some important alloys:

Aluminum Alloys

• AA-8000: used for building wire
• Al-Li (aluminum-lithium): used in aerospace applications
• Al-Cu (aluminum-copper): used in electrical wiring and cookware

Lithium Alloys

1. Lithium-sodium alloy (lithium, sodium)
2. Lithium-mercury alloy (lithium, mercury)

Alnico Alloys

1. Alnico (aluminum, nickel, copper)

Duralumin Alloys

1. Duralumin (copper, aluminum)

Magnalium Alloys

1. Magnalium (aluminum, 5% magnesium)

Magnox Alloys

1. Magnox (magnesium oxide, aluminum)

Nambe Alloys

1. Nambe (aluminum plus seven other unspecified metals)

Silumin Alloys

1. Silumin (aluminum, silicon)

Zamak Alloys

1. Zamak (zinc, aluminum, magnesium, copper)

Aluminum Complex Alloys

1. Aluminum forms other complex alloys with magnesium, manganese, and platinum.

Bismuth Alloys

1. Wood’s metal (bismuth, lead, tin, cadmium)
2. Rose metal (bismuth, lead, tin)
3. Field’s meal
4. Cerrobend

Cobalt Alloys

1. Stellite (cobalt, chromium, tungsten or molybdenum, carbon)
2. Talonite (cobalt, chromium)
3. Ultimet (cobalt, chromium, nickel, molybdenum, iron, tungsten)

Copper Alloys

1. Beryllium copper (copper, beryllium)
2. Billon (copper, silver)
3. Brass (copper, zinc)
   • Calamine brass (copper, zinc)
   • Chinese silver (copper, zinc)
   • Dutch metal (copper, zinc)
   • Gilding metal (copper, zinc)
   • Muntz metal (copper, zinc)
   • Pinchbeck (copper, zinc)
   • Prince’s metal (copper, zinc)

1. Brass (copper and zinc)

2. Bronze (copper and tin)

3. Tombac (copper and zinc)

4. Aluminum bronze (copper and aluminum)

5. Arsenical bronze (copper and arsenic)

6. Bell metal (copper and tin)

7. Florentine bronze (copper, aluminum, or tin)

8. Glucydur (beryllium, copper, and iron)

9. Guanin (likely a manganese bronze of copper, manganese, with iron sulfides and other sulfides)

10. Gunmetal (copper, tin, and zinc)

11. Phosphor bronze (copper, tin, and phosphorus)

12. Ormolu (Gilt Bronze) (copper and zinc)

13. Speculum metal (copper and tin)

14. Constantan (copper and nickel)

15. Copper-tungsten (copper and tungsten)

16. Corinthian bronze (copper, gold, and silver)

17. Cunife (copper, nickel, and iron)

18. Cupronickel (copper and nickel)

19. Cymbal alloys (Bell metal) (copper and tin)

20. Devarda’s alloy (copper, aluminum, and zinc)

21. Electrum (copper, gold, and silver)

22. Hepatizon (copper, gold, and silver)

23. Heusler alloy (copper, manganese, and tin)

24. Manganin (copper, manganese, and nickel)

25. Nickel silver (copper and nickel)

26. Nordic gold (copper and aluminum)

Gallium Alloys

• Galinstan (gallium, indium, tin)

Gold Alloys

• Electrum (gold, silver, copper)
• Rose gold (gold, copper)
• White gold (gold, nickel, palladium, or platinum)

Indium Alloys

• Field’s metal (indium, bismuth, tin)

Iron or Ferrous Alloys

• Steel (carbon)
• Iron (carbon)
• Fernico (nickel, cobalt)
• Elinvar (nickel, chromium)
• Invar (nickel)
• Kovar (cobalt)
• Spiegeleisen (manganese, carbon, silicon)
• Ferroalloy

Ferro Alloys:

• Ferroboron (iron and boron)
• Ferrochrome (iron and chromium)
• Ferromagnesium (iron and magnesium)
• Ferromanganese (iron and manganese)
• Ferromolybdenum (iron and molybdenum)
• Ferronickel (iron and nickel)
• Ferrophosphorus (iron and phosphorus)
• Ferrotitanium (iron and titanium)
• Ferrovanadium (iron and vanadium)
• Ferrosilicon (iron and silicon)

Lead Alloys:

• Antimonial lead (lead and antimony)
• Molybdochalkos (lead and copper)
• Solder (lead and tin)
• Terne (lead and tin)
• Type metal (lead, tin, and antimony)

Magnesium Alloys:

• Magnox (magnesium and aluminum)
• T-Mg-Al-Zn (Bergman phase)
• Elektron (magnesium-based alloy)

Mercury Alloys:

• Amalgam (mercury with almost any metal except platinum)

Nickel Alloys:

• Alumel (nickel, manganese, aluminum, and silicon)
• Chromel (nickel and chromium)
• Cupronickel (nickel, bronze, and copper)
• German silver (nickel, copper, and zinc)
• Hastelloy (nickel, molybdenum, chromium, and sometimes tungsten)
• Inconel (nickel, chromium, and iron)
• Monel metal (copper, nickel, iron, and manganese)
• Mu-metal (nickel and iron)
• Ni-C (nickel and carbon)
• Nichrome (chromium, iron, and nickel)
• Nicrosil (nickel, chromium, silicon, and magnesium)
• Nisil (nickel and silicon)

Nitinol (nickel, titanium, shape memory alloy)

Potassium Alloys

1. KLi (potassium, lithium)
2. NaK (sodium, potassium)

Rare Earth Alloys

Mischmetal (various rare earths)

Silver Alloys

1. Argentium sterling silver (silver, copper, germanium)
2. Billon (copper or copper bronze, sometimes with silver)
3. Britannia silver (silver, copper)
4. Electrum (silver, gold)
5. Goloid (silver, copper, gold)
6. Platinum sterling (silver, platinum)
7. Shibuichi (silver, copper)
8. Sterling silver (silver, copper)

Tin Alloys

1. Britannium (tin, copper, antimony)
2. Pewter (tin, lead, copper)
3. Solder (tin, lead, antimony)

Titanium Alloys

1. Beta C (titanium, vanadium, chromium, other metals)
2. 6al-4v (titanium, aluminum, vanadium)

Uranium Alloys

1. Staballoy (depleted uranium with titanium or molybdenum)
2. Uranium may also be alloyed with plutonium

Zinc Alloys

1. Brass (zinc, copper)
2. Zamak (zinc, aluminum, magnesium, copper)

Zirconium Alloys

Zircaloy is a metal alloy made of zirconium and tin. Sometimes, it also contains niobium, chromium, iron, or nickel.

Alloy

An alloy is a mixture of two or more metals. Alloys are often stronger and more durable than pure metals.

Composition

The composition of an alloy is the percentage of each metal in the alloy.

Commercial Utility

The commercial utility of an alloy is the purpose for which it is used.

Examples of Alloys

• Phosphor Bronze: This alloy is made of copper and a small amount of phosphorus. It is used to make springs, boat propellers, and other electrical components.
• Aluminum Bronze: This alloy is made of copper and aluminum. It is used to make utensils, decorative articles, coins, and jewelry.
• Brass: This alloy is made of copper and zinc. It is used to make utensils, inexpensive jewelry, hose nozzles and couplings, standing dies, condenser sheets, and cartridges.
• Gun Metal: This alloy is made of copper, tin, and zinc. It is used to make guns, gears, and castings.
• Coinage Alloy: This alloy is made of copper and nickel. It is used to make coins.
• Solder: This alloy is made of lead and tin. It is used to solder, or join, two metals together.
• Stainless Steel: This alloy is made of iron, carbon, chromium, and nickel. It is used to make a variety of products, including cutlery, cookware, and building materials.

Minerals

Minerals are natural substances made up of chemicals. They have a fixed composition and specific physical properties. Some minerals are made up of only one element, like graphite and diamond (both forms of carbon). Others are made up of two or more elements, like quartz (silicon and oxygen) and calcite (calcium, carbon, and oxygen).

Uses of Minerals

Minerals are used in a variety of ways. Some are used to make everyday objects, like utensils, automobile parts, and cutlery. Others are used in more specialized applications, like meter scales, measuring tapes, and pendulum rods.

Here are some examples of how minerals are used:

• Invar: This alloy of iron and nickel is used to make meter scales and measuring tapes because it has a very low coefficient of thermal expansion, meaning it does not expand or contract much with changes in temperature.
• Duriron: This alloy of iron and silicon is used in laboratory plumbing because it is resistant to corrosion.
• Tungsten steel: This alloy of iron, tungsten, and chromium is used to make high-speed cutting tools because it is very hard and wear-resistant.
• Sterling silver: This alloy of silver and copper is used to make jewelry, art objects, and other decorative items.
• Type metal: This alloy of lead, antimony, and tin is used to make type characters for printing and decorative objects like statuettes and candlesticks. Most minerals are made up of two or more elements, like halite (NaCl) or rock salt. The most common types of minerals are silicates, oxides, sulphides, halides, and carbonates.

Minerals can be divided into two groups: metallic or ore minerals, and non-metallic minerals. Examples of non-metallic minerals include carbon and sulphur.

Here is a table of some common minerals, their composition, and their commercial uses:

Minerals

Chemical Compounds

• Atoms of elements usually combine with other atoms to form molecules of a compound.
• For example, two oxygen atoms combine to form a molecule of oxygen, written as O2.
• In a compound, atoms of different elements combine in specific ratios. For example, two iron atoms (Fe) combine with three oxygen atoms to form a molecule of iron oxide (Fe2O3).
• There are millions of known chemical compounds, with tens of thousands in common use.

Chemical Reactions and Chemical Change

• Chemical change happens all around us, from the rusting of iron to the digestion of food.
• A chemical reaction is a process in which one or more substances change into one or more new substances.
• Chemical reactions involve the breaking and forming of chemical bonds between atoms.
• Chemical reactions can be classified into several types, including:
• Combination reactions: Two or more substances combine to form a single product.
• Decomposition reactions: A single substance breaks down into two or more products.
• Single-replacement reactions: One element replaces another element in a compound.
• Double-replacement reactions: Two compounds exchange ions to form two new compounds.

Chemical changes happen when substances change into new substances with different properties.

Examples of chemical changes:

• When coal burns, it combines with oxygen to form carbon dioxide and water vapor.
• When iron rusts, it combines with oxygen to form iron oxide.
• When beer ferments, yeast converts sugar into alcohol and carbon dioxide.
• When concrete and cement set, they combine with water to form a hard, solid material.
• When food is digested, it is broken down into smaller molecules that can be absorbed by the body.

Characteristics of chemical changes:

1. The products of a chemical change have different properties than the reactants.
2. The mass of the products of a chemical change is equal to the mass of the reactants.
3. When substances are formed in different ways, they always have the same composition.

Chemical Composition:

• In substances like carbon dioxide (CO2), the ratio of carbon (C) to oxygen (O) is always 3:8 by weight, no matter how it is formed.

Energy Changes in Reactions:

• Chemical reactions can release or absorb energy. For example, burning coal in air releases energy as heat and light, while combining carbon and sulfur absorbs heat.

Chemical Equations:

• Chemical changes can be represented by equations. For instance, the burning of carbon (C) with oxygen (O2) to form carbon dioxide (CO2) can be written as:

$$ \mathrm{C}+\mathrm{O} _{2} \rightarrow \mathrm{CO} _{2} $$

• The small numbers below the elements (subscripts) indicate the number of atoms in each molecule.

• Another example is the reaction between hydrogen (H2) and chlorine (Cl2) to form hydrogen chloride (HCl):

$$ \mathrm{H} _{2}+\mathrm{Cl} _{2} \rightarrow 2 \mathrm{HCl} $$

• In this case, a coefficient (2) is added before HCl to show that two molecules of HCl are formed.

Chemical Reactions

There are many different types of chemical reactions. Two common types are double decomposition and oxidation.

Double Decomposition

In a double decomposition reaction, two compounds react to form two new compounds. For example, when magnesium sulfate ($MgSO_4$) reacts with sodium hydroxide (NaOH), sodium sulfate ($Na_2SO_4$) and magnesium hydroxide (Mg${(OH)_2}$) are formed.

Oxidation

Oxidation is a reaction in which a substance combines with oxygen. For example, when iron is exposed to oxygen, it rusts. This is because the iron combines with oxygen to form iron oxide.

Oxidation and Reduction

• Oxidation is a process where atoms or molecules lose electrons.
• Reduction is a process where atoms or molecules gain electrons.
• Oxidation and reduction always happen together.

Example

When hydrogen gas ($H_2$) reacts with copper oxide (CuO), the copper oxide is reduced to copper (Cu) and the hydrogen gas is oxidized to water ($H_2O$).

Chemical Reactions

• Chemical reactions can happen slowly, like rusting, or quickly, like an explosion.
• The speed of a chemical reaction can be increased by using a catalyst, which is a substance that helps the reaction happen without being changed itself.

Air

• Air is a mixture of gases that surrounds the Earth.
• Air is made up of 78% nitrogen, 21% oxygen, and small amounts of other gases like argon, carbon dioxide, neon, helium, ozone, and water vapor.
• Air also contains pollutants.
• Air is made up of different gases.
• We can separate these gases and mix oxygen and nitrogen to make air.
• Air does not conduct heat well.
• Oxygen in the air helps things burn and allows us to breathe. Nitrogen reduces the effect of oxygen.
• Carbon dioxide is released into the atmosphere when things burn and when we breathe. Water vapor is created when water evaporates from the sea, rivers, and ponds.

Water Vapor in the Air

• Air contains about 0.4% water vapor.
• If we put a glass of ice cubes in the open air, the outside of the glass will become covered in water droplets. This is because the water vapor in the air condenses on the cold surface of the glass.

Carbon Dioxide

• Air contains about 0.03% carbon dioxide.
• If we put limewater in the open air, it will turn milky because it absorbs carbon dioxide from the air.

Water

• In the eighteenth century, Cavendish showed that water is a chemical compound.
• Water is made up of hydrogen and oxygen. There are two hydrogen atoms for every one oxygen atom.
• Water can be made by combining hydrogen and oxygen with electricity. For every one part of hydrogen, eight parts of oxygen are needed.
• Water boils at 100 degrees Celsius and freezes at 0 degrees Celsius.

Hard and Soft Water

• Hard water does not make soap lather easily.
• Soft water makes soap lather easily.

Types of Hardness in Water

• Temporary hardness is caused by calcium and magnesium bicarbonates. It can be removed by boiling or adding lime.
• Permanent hardness is caused by calcium and magnesium sulphates and chlorides. It can be removed by adding washing soda or distilling the water.

Rain Water

• Rainwater is the purest form of water because it is free from impurities.

Condensed Water Vapor: Water vapor in the air that has turned into liquid water. It’s soft because it doesn’t have certain salts like bicarbonates, sulphates, and chlorides of calcium and magnesium.

River Water: As river water flows over the earth’s surface, it picks up minerals from the soil and becomes hard water. It also contains various pollutants.

Oxygen: A gas that doesn’t have any color, smell, or taste. It doesn’t dissolve easily in water and is a bit heavier than air. Oxygen doesn’t burn on its own but helps other things burn. It’s found a lot on Earth, both by itself and mixed with other elements.

How to Get Oxygen: In a lab, you can heat potassium chlorate and manganese dioxide together to make oxygen. You can also get small amounts of oxygen by heating things like oxides or salts that have a lot of oxygen in them. Another way to get oxygen is to pass an electric current through water.

Why Oxygen is Important: Plants and animals need oxygen to breathe, and it’s also essential for almost all types of burning.

Hydrogen

• Atomic mass: 15.999
• Melting point: -218.4 degrees Celsius
• Boiling point: -183.0 degrees Celsius
• Density at 0 degrees Celsius: 1.329 kilograms per cubic meter
• Valency: 2

Hydrogen is:

• A colorless, highly flammable gas
• The lightest of all known substances
• Most abundant element in the universe
• Found in volcanic gases
• Burns with a pale blue flame
• Does not help combustion
• Slightly soluble in water
• Used in the manufacture of vanaspati ghee, alcohol, and ammonia
• Can be obtained from water, acids, and alkalies
• Prepared in a laboratory by the action of dilute sulfuric acid on commercial zinc

Atomic Number: 1 Relative Atomic Mass: 1.008 Melting Point: -259.14 degrees Celsius Boiling Point: -252.5 degrees Celsius Density: 0.08988 kilograms per cubic meter Valency: 1

Nitrogen

• A colorless, tasteless, and odorless gas
• Makes up nearly four-fifths of the Earth’s atmosphere
• Essential for plant growth
• Used in the manufacture of fertilizers, explosives, and plastics

• Nitrogen makes up about 78% of the air we breathe.
• It is a gas that does not burn or help other things burn.
• It dissolves a little bit in water.

How to make nitrogen

• In a lab, you can make nitrogen by heating ammonium nitrite.
• On a large scale, you can get nitrogen from the air. First, you liquefy the air, then you let it evaporate. Nitrogen evaporates first, leaving oxygen behind.

Some facts about nitrogen

• Atomic number: 7
• Melting point: -209.86 degrees Celsius
• Valencies: 3 and 5
• Relative atomic mass: 14.007
• Boiling point: -195 degrees Celsius

Carbon Dioxide

• Carbon dioxide is a colorless, odorless gas that is heavier than air.
• It is produced when we breathe, when things burn, and when organic matter decomposes.
• Carbon dioxide is acidic and can turn limewater milky.

How to make carbon dioxide

• You can make carbon dioxide by reacting dilute acids with carbonates.
• You can also make it by fermenting sugar.
• In a lab, you can make it by treating marble pieces with hydrochloric acid.

Uses of carbon dioxide

• Carbon dioxide is used in food refrigeration, carbonated beverages, and fire extinguishers. In Table 10.4, there is a row about hydrochloric acid. It says that hydrochloric acid is found in digestive juices. This means that hydrochloric acid is a natural acid that is produced by our bodies.

Industrial Chemistry

Soaps

• Soaps are made from fats and oils that have been reacted with an alkali, such as sodium hydroxide or potassium hydroxide. The resulting product is a salt of a fatty acid, which is a long chain of carbon atoms with a carboxyl group (-COOH) at one end.
• Soaps have two ends: a charged end that attracts water and a hydrocarbon end that attracts oil. This allows them to dissolve both water and oil, which is why they are so good at cleaning.

Cleansing Action of Soaps

• When you wash something with soap and water, the soap molecules surround the dirt and oil on the surface. The charged end of the soap molecule attracts the water, while the hydrocarbon end attracts the oil. This causes the dirt and oil to be suspended in the water, so that it can be rinsed away.

Glass

• Glass is a combination of different materials, including sand (silica), soda ash (sodium carbonate), and lime stone (calcium carbonate).
• These materials are mixed together and heated to a very high temperature until they melt and form a liquid.
• The liquid is then shaped into different objects, such as bottles, windows, and cups.

Cement

• Cement is a material used to make concrete.
• It is made by mixing together limestone, clay, and a small amount of gypsum.
• The mixture is heated until it forms a clinker, which is then ground into a powder.
• When the powder is mixed with water, it forms a paste that can be used to make concrete.
• Portland cement is the best type of cement.
• It is made up of different materials, including calcium oxide, iron oxide, magnesium oxide, alkali, silicon dioxide, sulfur trioxide, and aluminum oxide.

How cement is made:

• The raw materials are crushed and mixed together.
• The mixture is ground into a fine powder.
• The powder is heated in a kiln at a very high temperature.
• This causes the calcium oxide to combine with the aluminum silicate to form calcium silicate and aluminate.
• Gypsum is added to the mixture, and it is ground again to form cement.

Coal:

• Coal is formed from the remains of plants that lived millions of years ago.
• When coal is heated in the absence of air, it produces coke and volatile matter.
• Coke is a solid residue, and volatile matter includes coal gas and liquid.

Organic Chemistry

Carbon Compounds

• Before 1828, scientists thought that organic compounds could only be found in living things. They believed that a special “vital energy” was needed to make organic compounds.
• In 1828, a German chemist named Friedrich Wohler proved this theory wrong. He made an organic compound called urea in his lab by evaporating a solution of an inorganic compound called ammonium cyanide.
• Today, we know that organic chemistry is the study of carbon compounds.

Organic and Inorganic Compounds

• Most organic compounds can be burned, while most inorganic compounds cannot.
• Most organic compounds are gases or liquids at room temperature, while most inorganic compounds are solids.

Solids and Liquids

• Most organic compounds are liquids or solids with relatively low melting points.
• Most inorganic compounds are solids with high melting points.
• While most organic compounds are insoluble in water, most inorganic compounds are soluble.

Carbon

• Carbon is the twelfth most abundant element in the Earth’s crust.
• It is unique because it can easily combine with itself to form large molecules of carbon atoms linked in long chains or rings.
• There are more than a million different combinations of carbon atoms.

Different Forms of Carbon

• There are many different forms of carbon, including diamond, graphite, charcoal, lamp black, coke, gas carbon, coal, and animal charcoal.

Allotropic Forms of Carbon

• When a substance exists in different crystalline modifications, it is called allotropy.
• The different forms of the substance are called allotropes.
• Carbon shows allotropy because it exists in different forms. Carbon can take different forms, called allotropes. Two of these allotropes are diamond and graphite.
• Coke, charcoal, and lamp black were once thought to be shapeless forms of carbon. However, we now know that they all contain tiny crystals of graphite.
• Diamond and graphite have different structures and properties, but they share the same chemical symbol, C. They both react with oxygen to produce carbon dioxide when heated strongly.
• Diamond is the hardest natural substance known. Its name comes from the Greek word “adamas,” which means invincible. It is the purest form of carbon.

Diamonds:

• Diamonds are made of pure carbon.
• They are very hard and can’t be scratched by anything else.
• Diamonds don’t let heat or electricity pass through them.
• They don’t react with chemicals, but they can burn in the air if they are very hot.
• Diamonds don’t dissolve in any liquids.

Synthetic Diamonds:

• Since 1955, people have been able to make diamonds in a lab.
• They do this by heating and pressurizing carbon compounds.

Uses of Diamonds:

• Clear diamonds are used in jewelry.
• Dark diamonds are used to make cutting tools.

Famous Diamonds:

• The Koh-i-Noor is the most famous diamond in the world.
• It was mined in India, but the British took it.
• The Cullinan is the largest diamond in the world.
• It was found in South Africa in 1905.

Graphite:

• Graphite is a dark gray solid.
• It feels soapy and shiny.
• Graphite conducts electricity and heat well.
• It is used to make pencils. - When graphite is mixed with acids or alkalies, it undergoes a chemical change. However, when it is heated with nitric acid, it forms graphite acid.
• Graphite is used as a lubricant, in paints, for making electrodes, and in lead pencils.
• Pure graphite is made by heating coke in an electric furnace at a temperature of about 2500 degrees Celsius without air.

Petroleum

• Petroleum is a mixture of hydrocarbons that is thought to have come from the breakdown of animal and plant fats under high pressure and temperature.
• Fractional Distillation is a process that separates petroleum into different products based on the fact that lower hydrocarbons boil at a lower temperature than higher ones.
• A naturally occurring, flammable liquid found in the Earth’s crust.
• Used to make gasoline, diesel, and other products.

Seperate Petroleum Products:

Ether

• A colorless, flammable liquid that is used as a solvent and an anesthetic.

Petrol or gasoline

• A flammable liquid used to power cars and other vehicles.

Kerosene oil

• A flammable liquid used for heating and cooking.

Gas oil, diesel, or heavy oil

• A flammable liquid used to power trucks, buses, and other heavy vehicles.

Lubricating oils, gaseous and petroleum jelly

• Used to lubricate machinery and engines.

Paraffin (wax)

• A solid, waxy substance used to make candles, boot polish, and other products.

Asphalt, petroleum coke (Bitumen and coke)

• A black, sticky substance used to pave roads and make roofing materials.

Liquefied Petroleum Gas (LPG)

• A mixture of hydrocarbons such as propane, butane, and pentane.
• Used as a fuel for cooking, heating, and transportation.

Liquefied Petroleum Gas (LPG)

• LPG is a mixture of propane and butane gases.
• These gases are stored in cylinders under pressure to keep them in a liquid state.
• Cooking gas cylinders contain LPG in liquid form.

Synthetic Rubber

• Synthetic rubber is made from certain hydrocarbons through a process called polymerization.
• Some examples of synthetic rubber include:
  • Neoprene: made from chloroprene
  • BUNA-S: made from styrene and butadiene
  • BUNA-N: made from butadiene and acrylonitrile
• Rubber is made harder by a process called vulcanization, which involves heating rubber with sulfur.

Synthetic Fibers

• Nylon: the first synthetic fiber, made from adipic acid and hexamethylene diamine
• Terylene: made from terephthalic acid and ethylene glycol

Plastics

• Plastics are synthetic materials that are neither rubber nor fiber but are used as substitutes for these materials.
• Plastics are also polymers, made from a variety of raw materials, including:
  • Polyethylene (PE)
  • Polyvinyl chloride (PVC)
  • Polystyrene (PS)
  • Polypropylene (PP)

Polyethylene

• Polyethylene is a plastic made from ethylene gas.
• Ethylene gas is put under pressure and heated in the presence of a catalyst.
• This causes the ethylene gas molecules to link together to form long chains.
• These long chains are what make up polyethylene plastic.

Radioactivity

• Radioactivity is when an atom breaks down and releases energy.
• This can happen naturally or be caused by humans.
• When an atom breaks down, it can release different types of radiation, including alpha, beta, and gamma rays.
• Alpha rays are the least harmful, while gamma rays are the most harmful.
• Radioactivity can be used for good, such as in medicine and power generation.
• However, it can also be used for bad, such as in nuclear weapons.

Radioactive Emissions

Sub-atomic Particles (Radiation)

1. Alpha $(\alpha)$ particles: These are positively charged helium atoms that can’t penetrate very far. They can be stopped by a sheet of paper or aluminum foil.
2. Beta ( $\beta$ ) particles: These are negatively charged light particles that can penetrate more than alpha particles.

Penetrating Particles (Radiation)

These are also called Gamma $(\gamma)$ emissions. They are like light but have shorter wavelengths and higher energy. They can pass through several centimeters of lead.

X-rays

• X-rays are a type of radiation similar to light but can penetrate solids.
• X-rays are produced when cathode rays hit a metal with a high atomic mass, like tungsten.

X-ray Photographs

X-rays can pass through thick objects without being completely absorbed.

Nuclear Reaction and Atomic Energy

• Nuclear Reaction: When a nucleus is hit with a tiny particle like a neutron or proton, or with another nucleus, it can change into different things very quickly. The first time this was seen was in 1919 when Rutherford shot alpha particles at nitrogen.

• Nuclear Fission: Nuclear fission is when a big nucleus breaks into two smaller ones and releases a lot of energy. In 1939, Otto Hahn and F. Steersman from Germany found that when they shot slow neutrons at uranium, it split into two smaller pieces and made a lot of heat. This splitting of uranium is called nuclear fission.

Types of Nuclear Fission

1. Controlled Nuclear Fission: This type of fission happens in nuclear reactors. The rate of the fission reaction is slowed down, and the energy produced can be used for helpful things.
2. Uncontrolled Nuclear Fission: This type of fission happens in an atom bomb. The fission reaction is not controlled, and a lot of heat is produced. The process continues until all the fissionable material is used up.

The First Atom Bomb

On August 6, 1945, an atom bomb was dropped on the city of Hiroshima in Japan. The bomb was made of plutonium-239. On August 9, 1945, another atom bomb was dropped on the city of Nagasaki in Japan.

Nuclear Fusion

Nuclear fusion is a nuclear reaction where lighter atomic nuclei combine to form a heavier nucleus. This reaction also produces a lot of heat. If nuclear fusion can be controlled, it could be a great source of energy.

Atomic Energy (Nuclear Energy)

Atomic energy or nuclear energy is the energy that comes from nuclear fission or nuclear fusion.

Nuclear Energy

Nuclear energy, also known as atomic energy, is a type of energy that comes from the nucleus of an atom. When atoms are split apart, a lot of energy is released. This energy can be used to generate electricity or power machines.

How Nuclear Energy Works

Nuclear energy is created when the nucleus of an atom is split apart. This process is called nuclear fission. When an atom is split, it releases a lot of energy in the form of heat and radiation. This heat can be used to boil water and create steam, which can then be used to generate electricity.

Benefits of Nuclear Energy

Nuclear energy has a number of benefits, including:

• It is a clean source of energy. Nuclear power plants do not produce greenhouse gases, which contribute to climate change.
• It is a reliable source of energy. Nuclear power plants can operate 24 hours a day, 7 days a week, regardless of the weather.
• It is a relatively inexpensive source of energy. Nuclear power plants can produce electricity at a competitive cost compared to other sources of energy.

Risks of Nuclear Energy

There are also some risks associated with nuclear energy, including:

• The potential for nuclear accidents. Nuclear power plants are complex facilities, and there is always the potential for an accident to occur.
• The long-term storage of nuclear waste. Nuclear power plants produce radioactive waste, which must be stored safely and securely for thousands of years.
• The proliferation of nuclear weapons. Nuclear power plants can produce materials that can be used to make nuclear weapons.

Overall, nuclear energy is a complex technology with both benefits and risks. It is important to weigh the benefits and risks carefully before making a decision about whether or not to support nuclear energy. The pressure and volume of a gas are directly related to its temperature.

• The absolute temperature is measured from absolute zero, which is about -273 degrees Celsius.
• When the temperature of a gas increases by 1 degree Celsius, its pressure increases by 1/273 of its original pressure at 0 degrees Celsius.
• If the pressure of a gas stays the same, its volume will increase by 1/273 of its original volume at 0 degrees Celsius for every 1 degree Celsius increase in temperature.
• In other words, the volume of a gas is directly proportional to its absolute temperature when the pressure is constant.
• This principle was discovered by the French scientist Jacques Alexandre Charles.

Gay-Lussac’s Law

• Law of Gaseous Volume: This law says that when gases react with each other, the amounts of the gases that react and the amounts of the gases that are made are in simple whole number ratios. For example, one unit of nitrogen gas reacts with three units of hydrogen gas to make two units of ammonia gas.
• Law of Thermal Expansion: This law says that when you heat a gas, it will expand by the same amount for every degree that the temperature increases.

Hess’ Law

• This law says that the amount of heat that is released or absorbed in a chemical reaction is the same, no matter how many steps the reaction takes.

Graham’s Law of Diffusion:

• This law says that how fast two gases spread out (diffuse) depends on how heavy they are.
• The lighter the gas, the faster it will spread out.
• A Scottish chemist named Thomas Graham (1805-1860) discovered this law.

Henry’s Law:

• This law says that the amount of gas that dissolves in a liquid depends on the pressure of the gas.
• The higher the pressure, the more gas will dissolve in the liquid.
• This law was discovered by a British chemist named William Henry in 1803.

Lambert’s Law:

• This law says that when light passes through a material, the amount of light that is absorbed is the same for each layer of the material that is the same thickness.
• For example, if you have a piece of colored glass, the amount of light that is absorbed by the glass will be the same for each layer of glass that is the same thickness.

Raoult’s Law:

• This law says that the amount of vapor pressure that is lowered by a solute (something that is dissolved in a liquid) is proportional to the amount of solute that is dissolved in the liquid.
• The more solute that is dissolved in the liquid, the lower the vapor pressure will be.
• This law was discovered by a French chemist named Francois-Marie Raoult in 1887.

Law of Conservation of Mass and Matter

• Matter cannot be created or destroyed.
• The total amount of mass or matter in a system always stays the same, without any increase or decrease in quantity.

Important Chemical Processes

• Bessemer Process: This method turns pig iron into steel by blowing air through the melted metals to get rid of impurities like carbon, silicon, phosphorus, and manganese that are usually found in pig iron.
• Clemmensen Reduction: This process changes aldehydes and ketones into hydrocarbons by heating them with a mixture of zinc and hydrochloric acid.
• Gattermann Reaction: This process turns aromatic hydrocarbons into aldehydes by reacting them with carbon monoxide and hydrogen chloride in the presence of a copper catalyst. Haber Process: A method for making ammonia by combining nitrogen and hydrogen in the presence of a catalyst. Kolbe Reaction: A process for making hydrocarbons by passing electricity through a solution of the alkali salts of aliphatic carboxylic acids. Solvay Process: A method for making sodium carbonate from calcium carbonate and sodium chloride. The process involves heating calcium carbonate to produce calcium oxide and carbon dioxide, which is then bubbled into a solution of sodium chloride in ammonia. Sodium hydrogen carbonate is precipitated, which is then heated to produce sodium carbonate. Bayer Process: A method for extracting aluminium oxide from bauxite by treating it with hot caustic soda solution under pressure. Bergius Process:
• A method for making lubricants and synthetic fuel, like petrol, from coal.
• It involves heating a mixture of powdered coal, heavy oil or tar, and hydrogen under pressure.
• A catalyst like iron, tin, or lead is used in the process.
• Developed by German chemist Friedrich Bergius, who won the Nobel Prize in 1931. Bosch Process:
• A method for producing industrial hydrogen.
• It involves passing steam over extremely hot coke to create water gas (a mix of carbon monoxide and hydrogen).
• In the presence of a catalyst (a metal oxide), this water gas reacts with more steam to release hydrogen and carbon dioxide.
• Named after German chemist Carl Bosch (1874-1940). Down Process:
• A method for producing sodium metal.
• It involves the electrolysis of molten sodium chloride (NaCl).
• The molten sodium and calcium formed at the cathode are then separated. Frasch Process:
• A method for extracting sulfur from underground deposits.
• Superheated water is forced down into the deposits, melting the sulfur.
• The molten sulfur is then pumped up to the surface. Sulphur Mining:
• Sulphur is found underground in deposits.
• Compressed air is used to melt the sulphur.
• The melted sulphur is collected.
• This process was invented by Herman Frasch in 1891. Hall-Heroult Process:
• This process is used to make aluminum.
• Aluminum oxide is dissolved in cryolite.
• Electricity is passed through the mixture, which separates the aluminum from the oxygen.
• This process was developed in 1885 by Charles Hall in the US and P. T. Heroult in France. Parkes Process:
• This process is used to extract silver from lead ore.
• Molten zinc is added to molten lead ore.
• The lead separates from the silver, leaving zinc-silver.
• The zinc-silver is heated, which turns the zinc into a gas and leaves the silver behind. Brown-ring Test:
• This test is used to check for nitrates in a solution.
• Iron sulphate solution is added to the solution being tested.
• Concentrated sulphuric acid is carefully added to the side of the test tube.
• If nitrates are present, a brown ring will form at the junction of the two liquids. Flame Test: This test helps us identify specific elements. We dip a clean platinum wire into the mixture we want to test and heat it using a Bunsen flame. Different elements produce different flame colors. For example:
• Brilliant orange-yellow: Sodium
• Crimson: Strontium
• Apple green: Barium Beilstein’s Test: This test is used to detect the presence of halogens (like chlorine, bromine, or iodine) in an organic compound. We heat a clean copper wire in a flame until it stops producing a green flame. Then, we dip the wire into the solution we want to test and heat it again. If chlorine, bromine, or iodine is present, the flame will turn bright green. Fehling’s Test: This test helps us detect sugars and aldehydes in a solution. We mix equal amounts of copper sulfate solution (Fehling A) and sodium tartrate solution (Fehling B) in a test tube. If the solution contains sugars or aldehydes, it will turn a reddish-brown color when heated. Ube: When ube is boiled with a specific solution, it forms a red precipitate if sugar or aldehyde is present. Kjeldahl Method: This method is used to measure the amount of nitrogen in an organic compound. The compound is boiled with concentrated sulfuric acid and copper sulfate (a catalyst) to convert the nitrogen into ammonium sulfate. Then, an alkali is added to the mixture, and it is boiled again to distill off ammonia. This ammonia is passed into a standard acid solution and measured by titrating the solution. Molish’s Test: This test is used to detect carbohydrates in a solution. A small amount of alcoholic alpha-naphthol is mixed with the solution being tested, and concentrated sulfuric acid is slowly poured down the side of the test tube. If a deep violet ring forms when the two liquids meet, it indicates the presence of carbohydrates. Rast’s Method: This method is used to determine the molecular weight of a substance by measuring how much the freezing point of camphor is lowered when a known weight of the substance is added to it. Schiff’s Test: This test is used to distinguish between aldehydes and ketones. When an aldehyde is mixed with Schiff’s reagent (a solution of fuchsin and sulfurous acid), it forms a purple or red color. Ketones do not react with Schiff’s reagent. Aldehydes and Ketones Aldehydes and ketones are two types of organic compounds. Aldehydes have a carbonyl group (C=O) at the end of a carbon chain, while ketones have a carbonyl group in the middle of a carbon chain. Schiff’s Reagent Schiff’s reagent is a solution of rosaniline and sulphurous acid. It is used to test for the presence of aldehydes. When an aldehyde is added to Schiff’s reagent, it oxidizes the reduced form of the dye rosaniline back to its original magenta colour. Testing for Aldehydes and Ketones Aldehydes restore the colour of Schiff’s reagent immediately, while ketones restore the colour slowly. This difference can be used to distinguish between aldehydes and ketones.

Common Substances and Their Chemical Compositions

The table below lists some common substances and their chemical compositions.

Chemical