physical properties across period 3

what happens to atomic radius across period 3?

It decreases from Na to Ar due to increasing nuclear charge with the same number of electron shells.

why does atomic radius decease across period 3?

Increasing proton number increases attraction between nucleus and electrons.

how does ionic radius change for Na⁺, Mg²⁺, Al³⁺?

ionic radius decrease as ionic charge increases

why are positive ions smaller than their atoms?

they lose electrons and experience stronger nuclear attraction

describe the melting point trend across period 3?

increases from Na to Al, peak at Si, then decreases from P to Ar

why does silicon have a high melting point?

it has giant covalent structure with strong covalent bonds

which period 3 elements conduct?

Na, Mg and Al due to delocalised electrons