Periodicity

Question 0

what happens to shielding as you go across a period?

Answer 0

stays the same - electron shells remain the same

Question 1

what is periodicity?

Answer 1

trends in properties across a PERIOD shown across the next PERIOD

Question 2

what happens to atomic radius as you go across a period?

Answer 2

1) Nuclear charge increases
2) Shielding stays the same

Therefore, force of attraction between nucleus and electrons increases

Question 3

what is first ionisation energy?

Answer 3

Enthalpy change for this process: give example

E.g Na(g) -> Na+ + e-

Question 4

what happens to 1st ionisation energy as you go across a period?

Answer 4

Increases because nuclear force increases but shielding remain the same therefore the strength of attraction between the nucleus and the outermost electron increases, requiring more energy to overcome

Question 5

how do you measure atomic radius?

Answer 5

internuclear distance/2

Question 6

what is key when judging 1st ionisation energy?

Answer 6

the POSITION of the outer electron - what sub-shell is it in

and

electrons in the orbitals - is there any repulsion?

Question 7

what is a metallic bond?

Answer 7

an electrostatic force of attraction between positive ions and delocalised electrons

Question 8

what is the difference between intermolecular and intramolecular forces?

Answer 8

inter = between molecules
intra = within molecules, between atoms in molecules