Question

Helium atom has an atomic mass of 4u and two protons in its neucleus how many neutrons does it have?​

Answer 1

protons will be 4 as

Atomic mass=protons= electrons

It would have 4+4=8 neutrons

Answer 2

☆$\red {HELLO\:DEAR}$☆

Helium atom has two neutrons.

The mass of an atom is the sum of the masses of protons and neutrons present in its nucleus.

Since helium atom has two protons, mass contributed by the two protons is (2 × 1) u = 2 u.

Then, the remaining mass (4 − 2) u = 2 u is contributed by 2u/1u = 2 neutrons.

☆$\green {VISHU\:PANDAT}$☆

☆$\blue {FOLLOW\:ME}$☆