Show diagramatically the electron distributions in a sodium atom and a sodium ion and also give their atomic number.

Explanation

Atomic number of sodium (Z) = 11
Mass number of sodium (A) = 23
`therefore` Number of protons in the nucleus = 11
Number of neutrons in the nucleus = 23-11=12
Number of electrons = 11
`therefore` Electronic configuration of Na atom = `{:(K, L, M ),(2, 8, 1 ):}`
`Na^(+)`ion is formed from sodium atom by loss of an electron (present in the outermost shell). Hence, its electronic configuration is `{:(K, L),(2, 8 ):}`. However, number of protons and neutrons remains the same.