Magnesium, on the left of Periodic Table, is more metallic than chlorine on the right of this Period. Why is this? - Because Magnesium has

Magnesium is more metallic than chlorine because elements with metallic character readily lose electrons. Magnesium has an ionic charge of +2, ie. it will lose 2 electrons if possible. Chlorine has an ionic charge of -1, means that it will gain 1 electron if possible.

They are all decomposition reactions.

Ithink is d. physical property