Periodicity

Question 1

Periodic table order is due to

Answer 1

proton number

Question 2

Atomic radius along a period?

Answer 2

decreases
increased nuclear charge
same number of electron shells
greater attraction for outer electron

Question 3

Atomic radius down a group?

Answer 3

Increases
Extra electron shells as you go down
Increases distance between +vely charged nucleus and outer electrons
Shielding
Reduced nuclear attraction

Question 4

IE along a period?

Answer 4

Increases
Decreasing atomic radius
Increasing nuclear charge due to more protons but same electron shielding
Outer electrons held more strongly
More energy required to remove electron

Question 5

IE down a group?

Answer 5

Decreases
Nuclear attraction decreases
Increasing shielding
Less energy needed to remove the outer electron

Question 6

Trend in melting points across period 3?

Answer 6

Na, Mg, Al have increasing electrons donated to the electron sea in the metallic lattice
Silicon is macromolecular with a very strong covalenf structure + highest mp
P, S, Cl are weak covalent molecules with weakening VDWs so lowest bp
Argon is most stable and has the lowest bp due to weakest VDW