3.2.2-3 Group 2 and Group 7

Question 1

how does boiling point change in group 7 elements?

Answer 1

BP INCREASES because:
- size of the molecule increases so there are more electron shells
- london forces get stronger so more energy is needed to overcome them

Question 2

how does electronegativity change in group 7 elements?

Answer 2

electronegativity DECREASES because:
- size of the atom increases as there are more shells so more shielding
- nuclear attraction on the bonding pair of electrons gets weaker

Question 3

how does reactivity change in group 7 elements?

Answer 3

reactivity DECREASES because:
- size of the atom increases, number of shells increases, more shielding
- gets more difficult to gain an electron onto the last shell

Question 4

how does oxidising power change in group 7 elements?

Answer 4

oxidising power DECREASES down the group because:
- size of the atom increases, more shells, more shielding
- nuclear attraction on the electron being gained decreases
- gets more difficult to accept electrons

Question 5

what are the halogens at room temp?

Answer 5

fluorine - pale yellow gas
chlorine - green gas
bromine - red-brown liquid
iodine - grey-black solid

Question 6

what are the halogens in water/cyclohexane?

Answer 6

fluorine - pale yellow
chlorine - green
bromine - orange-brown
iodine - dark brown/violet