Periodic Classification and Periodic Properties 2 Question 4
4. The statements that is/are true for the long form of the periodic table is/are
(1988, 1M)
(a) it reflects the sequence of filling the electrons in the order of sub-energy level $s, p, d$ and $f$
(b) it helps to predict the stable valency states of the elements
(c) it reflects tends in physical and chemical properties of the elements
(d) it helps to predict the relative ionicity of the bond between any two elements
Show Answer
Answer:
Correct Answer: 4. (a)
Solution:
| Element | Period No. |
Group No. |
|---|---|---|
| $\mathrm{C}$ | 2nd | 14 |
| ( $\mathrm{Al}$ | $3 \mathrm{rd}$ | 13) Along the period atomic radius |
| ${\mathrm{s}$ | $3 \mathrm{rd}$ | $16}$ decreases, so, radii : $\mathrm{Al}>\mathrm{S}$. |
| Cs | 6th | 1 |
With the addition of a new shell, period number as well as atomic radius increases. It is because of the successive addition of one extra shell of electrons. So, the order of the atomic radii of the given elements will be: $\mathrm{C}<\mathrm{S}<\mathrm{Al}<\mathrm{Cs}$
