Boron has two stable isotopes, ¹°B(19%) and ¹¹B(81%). Average atomic weight for boron in the periodic table is

Options

(a) 10.8
(b) 10.2
(c) 11.2
(d) 10

Correct Answer:

10.8

Explanation:

Avg Atomic Mass = (RA1 x MN1 + RA2 x MN2) / (RA1+ RA2)
Where RA= Relative Abundance, MN= Mass Number
= 19 x 10 + 81 x 11 / 100 = 10.81