2Na+O2--->Na2O2
4Na+O2--->2Na2O
2Na+Na2O2--->2Na2O
2Na+2H2O--->2NaOH+H2
2Na+2HCl--->2NaCl+H2
2Na+Cl2--->2NaCl
2Na+H2--->2NaH
2Na+CuSO4+2H2O--->Cu(OH)2+Na2SO4+H2