Which one of the samples contains the most molecules? o
A. 1 mol of CO2(g)
B. 1 mol of UF6(g)
O C. 1 mol CH3COOH()
D. They all have the same number of molecules

D is right

Explanation: One mole contains 6.0225 ·10^23 molecules

Despite of the substance

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

plasma is the state of matter where the substance is ionized and has no definite shape or volume. the fact of being ionized makes the substance a good electrical conductor.