Answer:
D
Explanation:
Nuclear binding energy curve. During the nuclear splitting or nuclear fusion, some of the mass of the nucleus gets converted into huge amounts of energy and thus this massis removed from the total mass of the original particles, and the mass is missing in the resulting nucleus.
Elements are separate particles that contain the properties of only one type of element (pure substance) and an atom represents that element as the smallest non divisible particle that retains the properties of that element. Compounds can be formed by conjoining different atoms together in different ratios and shapes, so a combination of elements.
1s^2 2s^2 2p^6 for the Mg2+ ion.