Question

In the module of chapter-Metals and Non Metals,you have explained the case of lithium metal,at the atomic level,that why it is so reactive (because there are 3 protons attracting the Valence electron, and 2 electrons in the k-shell repelling the valence electron, thats why the net resultant force is less) So can you please explain me the case of Sodium and calcium that why less energy is required to kick out valence electrons,like you have explained in the case of litium i.e at the Atomic level

Answer 1

Lithium metal is reactive as it has 1 electron in its valence shell which can easily remove to get a stable configuration of He. Sodium is next element of the same group and also has 1 electron in its valence shell. So it is also a reactive metal but is bigger than Lithium. As the size of the atom increases down in the group, the atomic radius increases so nuclear attraction decreases on valence electrons. Therefore it requires less energy to take out the valence electron from sodium compares to Lithium.
Calcium is the element of group-2 in the periodic table and is located in the same period of sodium. As we move across the period, the atomic size decreases. That increases the nuclear attraction which requires more energy to remove the electron from the valence shell.