Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
Solution:
Given: Atomic mass of helium atom = 4u, 2 protons in helium nucleus
Atomic mass = number of protons + number of neutrons
4 = 2 + number of neutrons
Number of neutrons = 4 – 2 = 2
Hence, Helium has 2 neutrons.
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