The smallest unit of matter that displays the physical and chemical properties of a compound ​

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

Suppose you wanted to make 100 grams of water. what is the molar mass of water (h2o)?

Given the following information: mass of proton = 1.00728 amu mass of neutron = 1.00866 amu mass of electron = 5.486 × 10^-4 amu speed of light = 2.9979 × 10^8 m/s calculate the nuclear binding energy (absolute value) of 3li^6. which has an atomic mass of 6.015126 amu. j/mol.