How many neutrons are in an atom of He?

Answer 1

In total nine different isotopes of helium are known to exist.

Helium 3 (one neutron) and helium 4 (two neutrons, by far the most common isotope) are the only stable isotopes. The other 7 isotopes (helium 2, 5, 6, 7, 8, 9, and 10) are unstable and rapidly decay into stable isotopes.

Answer 2

An Ne atom has more mass. Neon averages a mass of about 20 AMU, while helium usually has a mass of about 4.

Answer 3

The difference in atomic number between helium (He = 2) and neon (Ne = 10) is 8.

Answer 4

An atom of helium typically has 2 neutrons. Helium is composed of 2 protons and usually 2 neutrons, making its most common isotope helium-4.

Answer 5

8