Question

42.
132 amu of B12 will contain:
(a) 12NA atoms of boron
(b) 1 atom of boron
c )1 molecule of boron
d) NA molecules of boron​

Answer 1

Answer:

Option (a) 12NA atoms of boron

132 amu Boron-12 contains 12 atoms of B-12.

Explanation:

Provided that:

The mass (m) of some quantity of B-12 is 132 amu

We know that;

Boron's (B-12) atomic mass is 10.8 u or atomic mass unit (amu).

So, 132 amu of B12 will contain:

$number \: of \: B-12 \: atom \: = n \: (suppose) \\ n = \frac{132}{10.8} \: B-12 \: atoms \\ n = 12.22 \: B-12 \: atoms \\ \\ n ≈ 12 \: \: B-12 \: atoms$

So, 132 amu Boron-12 contains 12 atoms of B-12.