Boron has two isotopes B10 and B11 whose relative abundances are 20% and 80% respecctivly. Atomic weight of Boron is :A) 10B)11C)10.5D)10.8please show the answer with method
Average atomic mass = sum of product of relative abundance and atomic mass of isotopes.
Average atomic mass of boron =
= (10 x 20/100) + (11 x 80/100)
= 2 + 8.8
= 10.8 u
Hence, option D) is correct