How many photons of light are emitted when the electrons in 10 hydrogen atoms drop from energy level 5 to 3?

Someone help explain how to do this!!

Achemist 16 drop copper metal from copper chloride solution. the chemist place is 0.50 g of aluminum foil in a solution containing 0.75 g of copper (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction?

Identify the correct mole ratio for each substance. sodium chloride (nacl) na: cl = 1: ammonium nitrate (nhno) h: o = 4:

Which proportionality applies to avogadro’s law?