NEET Physics Nuclei Questions Solved


Atomic weight of boron is 10.81 and it has two isotopes B105 and B115. Then ratio of B105:B115  in nature would be 
(a) 19 : 81                  (b) 10 : 11
(c) 15 : 16                  (d) 81 : 19

(a) Let the percentage of B10 atoms be x, then Average atomic weight

=10x+11(100-x)100=10.81x=19      NB10NB11=1981

Difficulty Level:

  • 39%
  • 24%
  • 10%
  • 29%
Crack NEET with Online Course - Free Trial (Offer Valid Till August 27, 2019)