Answer:
The correct option is: b. Gallium
Explanation:
The energy levels, also known as the electron shells, refers to the orbits containing electrons that are found around the nucleus of an atom. They are denoted by the symbols K, L, M, N, and so on.
a. Potassium is a s-block element that belongs to the group 1 and period 4 of the periodic table. It has <u>four shells</u> and the number of electrons per shell is 2, 8, 8, 1. Therefore, it tends to <u>lose one valence electron</u> present in the valence shell to gain the noble gas configuration.
b. Gallium is a p-block element that belongs to the group 13 and period 4 of the periodic table. It has <u>four shells</u> and the number of electrons per shell is 2, 8, 18, 3. Therefore, it tends to <u>lose three valence electron</u>s present in the valence shell to gain the noble gas configuration.
c. Aluminum is a p-block element that belongs to the group 13 and period 3 of the periodic table. It has <u>three shells </u>and the number of electrons per shell is 2, 8, 3. Therefore, it tends to <u>lose three valence electrons</u> present in the valence shell to gain the noble gas configuration.
d. Germanium is a p-block element that belongs to the group 14 and period 4 of the periodic table. It has <u>four shell</u>s and the number of electrons per shell is 2, 8, 18, 4. Therefore, it tends to <u>lose or gain four valence electrons</u> present in the valence shell to gain the noble gas configuration.
<u>Therefore, Gallium is the only element that has four energy levels and tends to lose three valence electrons.</u>