why do scientists create models to describe atoms

Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction: 2al(s)+3cl2(g)→2alcl3(s) what is the maximum mass of aluminum chloride that can be formed when reacting 32.0 g of aluminum with 37.0 g of chlorine? express your answer to three significant figures and include the appropriate units.

The number at the end of an isotope’s name is the number.

If 16.00g of hydrogen gas reacts with 126.73g of oxygen, how many grams of water are yielded? (both reactants are completely consumed in the reaction.)