Question

Na, mg, al, si, p, s, cl are element of third group.
1) which one of these are invert gas? why.
2) which one of them have valency 4
3) what kind of bone does it have. ionic or covalent.
3) which one of them are electropositive.pick any two element

Answer 1

1) Argon   [you have not mentioned but it belongs to this period]
2) Silicon
3) Ionic bond : sodium,chlorine     Covalent bond : mg,al,p,s
4) Electropositive elements : sodium, magnesium.

                                      Hope it helps................

Answer 2

Answer:

1. None of the above is the answer.

2. Silicon has valency 4.

3. Silicon and Phosphorus make covalent bonds.

4. Na and Mg are electropositive.

Explanation:

None of these are inert gases as none of them have their outermost shells filled.

The valency of Silicon is 4.

Only Silicon and Phosphorus make covalent bonds. Rest of the elements make ionic bonds.

Na and Mg are electropositive i.e. they lose electrons.