Question

please give me answer​

Answer 1

Explanation:

1.the element sodium belongs to group 1 of mendeleev's perodic table and the formula of oxides of elements is R20.

so formula of oxide of sodium is Na20

= Rb element also belongs to group 1 so formula of oxide is Rb20

2.the element silicon belongs to group 4 of mendeleev's periodic

table .the genral formula of oxide is RO2.

so the formula for oxide Si is SiO2.

Sn belongs to same group so formula of oxide is Sno2.

C belongs to same group so formula of oxide is Co2.

3.Ca belongs to group 2 of mendeleev's periodic table.the general

formula of oxide RO.

so formula for oxide of Ca is CaO.

Ba belongs to this group ,so formula of oxide is BaO

4.phosphorus belongs to group 5 . so general formula of oxide is

R2O5.

5.Cl belongs to group 7 with general formula R2O7 .

so formula of their oxide is Cl2O7

hope th8s helps you

Answer 2

Explanation:

sio²

rio²

nacl²

sio²

çao²

co²