What is the molarity of a solution containing 340 grams of calcium oxide dissolved in 4.00 liters of water?

Why is an elements atomic mass not listed as a whole number on the periodic table

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?

Which metal exist in liquid state and can be cut with knife ?