HELLLLLLLLLLLLP ME PLS 10 points pls

What do the symbols in parenthesis indicate?
CaCl2(aq) + 2AgNO3(aq)) → Ca(NO3)2(aq) + 2AgCl(s)

1 the catalyst used in the reaction

2 the number of atoms of each reactant and product

3 the physical state of each reactant and product

4 the number of units of each reactant and product