Question

Why do metals have low ionization energy?

Answer 1

Ionization energy:

The energy required to remove an electron from the outermost shell of an isolated gaseous atom is called Ionization energy.

Alkali metals:

1. It belong to the first group of the periodic table.
2. It consists of the elements: Lithium $\left(Li\right)$ , sodium $\left(Na\right)$ , potassium $\left(K\right)$ , rubidium $\left(Rb\right)$ , caesium $\left(Cs\right)$ , and francium $\left(Fr\right)$.

They have low ionization energy because of:

1. Size of the atom - when the size of the atom increases, the outermost electron moves far off from the nucleus and the nuclear attraction becomes weak. As a result, the outermost electron can be removed easily.
2. Stable electronic configuration.
3. Sheilding effect.