Get it on Google Play
2. Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
Answer :


Given, atomic mass of helium atom = 4 u and 2 protons in helium nucleus

We know that, atomic mass = number of protons + number of neutrons

So, 4 = 2 + number of neutrons

=> Number of neutrons = 4 – 2 = 2

Hence, Helium has 2 neutrons.