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
x+2=0
x=-2
The correct option is this: SODIUM IS VERY REACTIVE BECAUSE IT DOES NOT HAVE A FULL VALENCE SHELL.
For an atom to attain an octet form, it must have eight electrons in its outermost shell. Elements with eight electrons in their outermost shells are un-reactive. Sodium has only one electron in its outermost shell, this makes it to be very reactive because it is very willing to react with suitable elements in order to become stable.
I believe doctors use (3) Co-60 to treat ILWs. Uranium and Carbon are not used, and a different isotope of lead is used to be attached to monoclonal antibodies.
Explanation:
Certain materials, called conductors, allow electric charge to move pretty freely through them. ... Other materials, like plastic and rubber, are called insulators because they don't allow electric charges to move through them.