Question

How many valence electrons are present in the alkali metals and alkaline earth metals?

Answer 1

Valence electrons are those electrons present in the outermost shell or energy level in an atom.

1)The number of valence electrons present in the alkali metals is 1. They lose one electron to form ${\mathrm{M}}^{+}$ ions.

For example, sodium (Na) has an electronic configuration$1s^{2}2s^{2}2p^{6}3s^1$

After losing one electron, the electronic configuration will be $1s^{2}2s^{2}2p^6$

2) The number of valence electrons present in the alkaline earth metals is 2 . They lose two electrons to form ${\mathrm{M}}^{+2}$ ions.

For example, Magnesium (Mg) has an electronic configuration $1s^{2}2s^{2}2p^{6}3s^2$.

After losing one electron, the electronic configuration will be $1s^{2}2s^{2}2p^6$.

Hence, valence electrons are present in the alkali metals is one and alkaline earth metals are two.