Which contains more molecules: 1.00 mol h2o2, 1.00 mol c2h6, or 1.00 mol co?

I believe H2O2 has the most, because it also has the most atoms (34)
Hope that helps!!

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts