Which of these elements has the most chemically reactive atoms?
a. gold
b. argon
c. carbon
d. chlorine

Option d) is the correct answer.

Explanation:

When an atom is electronegative in nature then it will attract electrons towards itself.

Atomic number of chlorine is 17 and its electronic distribution is 2, 8, 7. In order to complete its octet chlorine requires one electron and also being electronegative in nature it will readily react.

Therefore, chlorine will have chemically reactive atoms.

Whereas atomic number of gold is 79 and it also requires one electron to completely fill its octet. But it is not electronegative in nature, hence it is less reactive than chlorine.

On the other hand, argon has completely filled shell so, it will be low in reactivity. Atomic number of carbon is 6 and it requires 2 electrons to complete its octet so, its reactivity is also less than chlorine.