Which of the following does not form a diatomic molecule? chlorine copper nitrogen hydrogen

One does not belong why? ice, gold ,wood ,diamond and table salt

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver