Silver and lead are special elements, where silver is insoluble in all halogen anions (like AgCl, AgI, AgBr) and lead is insoluble in sulphates and halogen anions ( PbSO4, PbCl2, etc.) Mercury is special because it is the only metal that is a liquid at room temperature hope this helps!!
Hi, I think the D since the moon rotates about once a month and these months have different amounts of days. an example would be February that can have like 28 or 29 in leap year
