writing chemical formulae and equations

Question 1

what is sodium, magnesium and copper and what are their chemical formulae?

Answer 1

they are metals (elements)
Na, Mg, Cu

Question 2

what is neon and argon and what are their chemical formulae?

Answer 2

they are noble gases (elements)
Ne, Ar

Question 3

what is fluorine, chlorine, bromine, iodine, hydrogen, nitrogen, oxygen and what are their chemical formulae?

Answer 3

they are diatomic elements
F2, Cl2, Br2, I2, H2, N2, O2

Question 4

what is the chemical formulae for
carbon monoxide, carbon dioxide, water, sulfur dioxide, nitrogen dioxide, ammonia gas, methane

Answer 4

they are compounds
CO, CO2, H2O, SO2, NO2, NH3, CH4