`3`

`4Al + 3O_2` $\xrightarrow{t^o}$ `2Al_2O_3` ( Nhôm oxit)

`4Na + O_2 → 2Na_2O` ( Natro oxit )

`3Fe + 2O_2` $\xrightarrow{t^o}$ `Fe_3O_4` ( oxit sắt từ )

`4` 

`2Na + 2H_2O → 2NaOH + H_2` ( Natri hidroxit)

`CaO + H_2O → Ca(OH)_2` ( Canxi hidroxit)

`N_2O_5 + H_2O → HNO_3` ( axit nitric)

`2K + 2H_2O → 2KOH + H_2` ( Kali hidroxit)

`P_2O_5 + 3H_2O → 2H_3PO_4` ( axit photphoric)

 

$4Al+3O_2\xrightarrow{t^0}2Al_2O_3$

 $Al_2O_3:$

Nhôm oxit 

$4Na+O_2\xrightarrow{t^0}2Na_2O$

$Na_2O:$ Natri oxit 

$3Fe+2O_2\xrightarrow{t^0}Fe_3O_4$

$Fe_3O_4:$Oxit sắt từ 

$2Na+2H_2O \to 2NaOH+H_2$

$NaOH:$Natri hiđroxit 

$CaO+H_2O \to Ca(OH)_2$

$Ca(OH)_2:$Canxi hiđroxit 

$N_2O_5+H_2O \to 2HNO_3$

$HNO_3:$Axit nitric 

$2K+2H_2O \to 2KOH+H_2$

$KOH:$Kali hiđroxit 

$P_2O_5+3H_2O \to 2H_3PO_4$

$H_3PO_4:$Axit photphoric