A compound containing cobalt and oxygen has a mass of 7.500 grams. When heated, it breaks down to form 5.331 grams of cobalt. Calculate the empirical formula.

Can someone me out on this question for my national 5 chemistry homework

What physical property of gold makes panning a useful way to get gold from streams?

Achemist reacted 57.50 grams of sodium metal with an excess amount of chlorine gas. the chemical reaction that occurred is shown. na + cl2 → nacl if the percentage yield of the reaction is 86%, what is the actual yield? show your work, including the use of stoichiometric calculations and conversion factors.