Which pair of elements will form a covalent bond? A. Aluminium and Chlorine B. Carbon and Sulfur C. Lithium and Oxygen D. Potassium and Chlorine

Explanation:

Aluminum and chlorine form covalent bond.

Therefore,

Option A is correct✔

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

it's filtration, but this is an assumption so my apologies if i got this