Think about what you have learned about electrons, energy levels, and electron configurations. In 2 or 3 sentences, explain why an atom of Argon, Ar is less reactive (more stable) than an atom of Chlorine Cl.

Alr u see. argon is in group 8 of the periodic table, also known as noble gases. noble gases all have full shells, octect. this means that there is no chance for covalent or ionic bonding, no valence electrons available to bonding.

however, chlorine is in group 7 of the periodic table. this means to obtain a full octect shell, they will have to undergo covalent bonding to form a full octect shell.

hence, argon is more stable compared to chlorine

Adozen is 1221/12 = 1.751.75 x 12 = 21therefore, 1.75 is the answer.