Careva plss ???
Ex 2.1 Dau coroană am nevoie urgent

S+Fe=Fes
2Ca+O2=2CaO
2H2+O2=2H2O
AlCl3+3NaOh=Al(OH)3+3NaCl
2K+2H2O=2KOH+H2
3Fe+2O2=Fe3O4