Question

Helium atom has an atomic mass of 4 U and 2 Proton in its nucleus how many neutrons does it have

Answer 1

2 neutron because 2 are protones

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.

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