Search SchoolNGR

Saturday, 11 April 2026
Register . Login

An element X has isotopic masses of 6 and 7. if the relative abundance is 1 to 12.5 ...

An element X has isotopic masses of 6 and 7. if the relative abundance is 1 to 12.5 respectively, what is the relative atomic mass of X?
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
  • A 6.0
  • B 6.1
  • C 6.9
  • D 7.0
Correct Answer: Option C
Explanation:
Contribution by isotope 6 = 6 x 1 = 6
contribution by isotope 7 = 7 x 12.5 = 87.5
This contribution is made by 1 + 12.5 = 13.5 atoms
Relative atomic mass of = 87.5 + 6 = 93.5/13.5 = 6.9

Share question on: