Answer:
1)Na2O
let the valency of Na is x
2(x)+(2)=0
2x+2=0
2x=-2
x=-1
2)ZnO
let the valency of Zn is x
x+2=0
x=-2
3)Al2O3
let the valency of Al is x
2(x)+3(2)=0
2x+6=0
2x=-6
x=-3
4)MgO
let the valency of Mg is x
2
Explanation:
1)Valence number of Na=1 and O=2
1 2
Na O
Criss Cross it.
2)Valence number of Zn=2 and O=2
2 2
Zn O
Criss cross it then it will be ZnO. We can't write it as Zn202 we have to omit the numbers.
3)Valence number of Al in this compound is 2. The reason why I said this is because Aluminum has many valence numbers. And O=2
3 2
Al O
Criss cross it then it will be Al2O3.
4) Valence number of Mg=2 and O=2
Mg O
Criss cross it.
Hope it helps!
GEL
