Question

Which has the maximum metallic character $Na$, $Li$ or $K$?

Answer 1

We have to know the metallic character which indicates the reactivity of metal. All metals have the tendency to lose electrons during the chemical reactions. Which indicates that the metals have low ionization energy. Because ionization energy is the energy required to remove the electron from the isolated gaseous atom. Hence, metals have low ionization energy and low electron affinity. Which means, metals have very little tendency to gain electrons.

Complete answer:
Among the given compounds, potassium has the most metallic character. Potassium is a chemical element having the symbol ‘K’ with atomic number $19$. In the periodic table the potassium is occupied in group one and period four.
The metallic character of potassium is higher than that of sodium and lithium. Because, the metallic character increases when moving down the group in the periodic table. And the ability to lose the electron from the valence shell is increasing. When compared with sodium and lithium, the size of potassium is higher than sodium and lithium. Thus, it can easily remove its valence electron from the outermost shell. Therefore, potassium has more metallic character than sodium and lithium.

Note:
We must have to remember that the metallic character mainly depends on the size of the atom. Because, the metallic character is the ability to lose the electron of an atom. Hence, when the size is increasing, the nuclear charge of the atom is decreasing, and it allows to lose the free electrons. The metallic character can be measured by using the number of valence electron. Hence, it also depends the distance from the nucleus and effective nuclear charge.