I need help on this science question

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?

Which of the following methods uses the decay of atomic particles in an object to find its exact age? a. fossil dating b. geologic dating c. radioactive dating d. relative dating

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system