Вариант 4:
№1 1) 2Na + Cl2 <span> → 2NaCl
2) 2H2S + O2 </span><span> → 2S + 2H2O
3) 4Al + 3O2 </span><span> → 2Al2O3
4) C + 2H2 </span><span> → CH4
№2 1) 4B + 3O2 </span><span> → 2B2O3 (при нагревании)
2) C + 2S </span><span> → CS2
№3 1) 2AgBr </span><span> → 2Ag + Br2
2) 2Na + H2 </span><span> → 2NaH</span>