Consider Zn + 2HCl → ZnCl2 + H2 (g). If 0.30 mol Zn reacts with HCl, how many grams of HCl are needed?

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

Express the following number in scientific notation. 0.026890 =

Particles vibrate in a rigid structure and do not move relative to their neighbors.