Acompound has 39 g of potassium and 78 g of selenium. what is the mass ratio of potassium and selenium in the compound

What type of organic molecule comprises the majority of a potato?

Stoichiometry- i need with 14 and 15! an explanation would be appreciated!

The nonmetals in groups 6a and 7a a) end in -ate b) have a numerical charge that is found by subtracting 8 from the group number c) all have ions with a –1 charge d) lose electrons when they form ions