Question 23
[Maximum number: 1]
Atoms of sodium, rubidium and element Q each have one outer shell electron.
Some properties of these elements are shown.
What is Q ?
A
hydrogen
B
lithium
C
potassium
D
caesium
CAIE IGCSE Chemistry Predicting Alkali Metal Properties
Practise extrapolating Group I trends to identify an unknown element and predict melting point, density or reaction vigour from neighbouring data.
How this is tested
- place an unknown Group I element from its outer electron and relative-reactivity evidence
- extrapolate melting point or density from neighbouring values without reversing the trend
- predict a more vigorous reaction with water or oxygen for an element lower in the group