Some Basic Concepts Of Chemistry Question 163
Question: Boron has two stable isotopes, $ ^{10}B $ (19%) and $ ^{11}B $ (81%). The atomic mass that should appear for boron in the periodic table is [CBSE PMT 1990]
Options:
A) 10.8
B) 10.2
C) 11.2
D) 10.0
Show Answer
Answer:
Correct Answer: A
Solution:
Atomic mass $ =\frac{10\times 19+81\times 11}{100} $ $ =\frac{190+891}{100} $ $ =\frac{1081}{100} $
$ =10.81 $
