Explaining the trend in the reactivity of the halogens
3 marks · EasyBelow is a table of some Group 7 elements and their melting points.
| Element | Melting Point (°C) |
|---|---|
| Fluorine | -220 |
| Chlorine | -101 |
| Bromine | -7 |
| Iodine | 114 |
Describe the trend in melting point as you go down Group 7.
Predict whether astatine would have a higher or lower melting point than iodine. Give a reason for your answer.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Melting point increases down the group.
(b) Astatine would have a higher melting point than iodine because melting point increases down Group 7. · must show Astatine has a higher melting point than iodine, Melting point increases down the group
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States melting point increases down Group 7.
M1 (b) · 1 mark · Predicts astatine has a higher melting point than iodine.
A1 (b) · 1 mark · Supporting reason: melting point increases down the group.
Worked solution
a) Melting point increases down the group.
b) Astatine would have a higher melting point than iodine because the trend in Group 7 is that melting points increase as you go down the group.