PLEASE HELP!! WILL GIVE BRAINLIEST

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?

In a laboratory, 1.55mg of an organic compound containing carbon, hydrogen, and oxygen is burned for analysis. this combustion resulted in the formation of 1.45mg of carbon dioxide and .89 mg of water. what is the empirical formula for this compound?