DP Chemistry (last assessment 2024)
Question 17N.2.sl.TZ0.b
Date | November 2017 | Marks available | [Maximum mark: 2] | Reference code | 17N.2.sl.TZ0.b |
Level | sl | Paper | 2 | Time zone | TZ0 |
Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
17N.2.sl.TZ0.b
Trends in physical and chemical properties are useful to chemists.
Explain why the melting points of the group 1 metals (Li → Cs) decrease down the group.
[2]
Markscheme
atomic/ionic radius increases
smaller charge density
OR
force of attraction between metal ions and delocalised electrons decreases
Do not accept discussion of attraction between valence electrons and
nucleus for M2.
Accept “weaker metallic bonds” for M2.
