Question

Helium has an atomic mass of 4u and 2 protons in its nucleua. How many neutrons does it have. ​

Answer 1

Answer:

helium has two neutrons

atomic mass= protons+ neutrons

4=2+n

4-2=n that is n is 2

hope it helps

Answer 2

Explanation:

The mass of an atom is given by the sum of the masses of protons and neutrons present in the nucleus. Since helium atom has a atomic mass of 4 u and it has two protons. Two protons contribute 2 u to atomic mass. Hence, it must contain 2 neutrons.