Where do the numbers in a stoichiometry mole ratio come from

All cells are made of four types of acids, lipids, proteins, and carbohydrates.

Place the elements below in order of decreasing ionization energy. aluminum(al) chlorine(cl) magnesium (mg) sulfur(s)

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.