Predicting the properties of francium
2 marks · HardPredict whether francium would form coloured or colourless compounds in water, and explain your answer.
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Francium would form colourless compounds in water because, like other alkali metals, its compounds do not absorb visible light.
Also accept: Francium compounds would be colourless in water because they are similar to compounds of other Group 1 metals.; Francium forms colourless and soluble compounds in water as do other alkali metals.
Common mistakes: Saying francium forms coloured compounds like transition metals.; Not giving a reason.
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Marking points
B1 · 1 mark · States that francium would form colourless compounds in water.
M1 · 1 mark · Provides correct explanation based on similarity to other Group 1/alkali metals (compounds do not absorb visible light, or reference to trend).
Worked solution
Francium would form colourless compounds in water because, like other alkali metals, its compounds are colourless as they do not absorb visible light.