Question

Why is the atom X and the ion X²+ almost the same mass​

Answer 1

The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1 e and has the same mass as an electron.

Answer 2

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As we know that mass of atom is centered on the nucleus and there is the presence of Proton and Neutron but not electron.

So, Number of protons in X will be equal to Number of protons in X²+ because On formation of ion, electron gets loss or gain but proton remains same.

So, we can say that atom X and the ion X²+ almost the same mass