CHEMISTRY

JAMB 2011 - Question 8

Chemistry 2011 JAMB Past Questions - Question 8: An isotope has an atomic number of 15 and amass number of 31. The number of protons it contains is

Choose the correct answers from the options given.
An isotope has an atomic number of 15 and amass number of 31. The number of protons it contains is
A:
B:
C:
D:
Examkits App

Examkit's JAMB CBT App

Practice JAMB offline with our Online, PC and Mobile App

  • ✅ 25+ years of past questions (2000 to 2025)
  • ✅ Video solutions and explanation to questions
  • ✅ E-library
  • ✅ Study by topic
  • ✅ And more.

Correct Answer

B

Explanation

An isotope with an atomic number of 15 has 15 protons. The atomic number represents the number of protons in an atom.

The mass number is the sum of protons and neutrons in the nucleus. In this case, the mass number is 31. Since the number of protons is 15, the number of neutrons can be calculated by subtracting the atomic number from the mass number:

Number of neutrons = Mass number - Atomic number
Number of neutrons = 31 - 15
Number of neutrons = 16

So, the correct answer is 15 protons.