This is about groups in the periodic table - AQA - GCSE Chemistry - Question 5 - 2022 - Paper 1
Question 5
This is about groups in the periodic table.
The elements in Group 1 become more reactive going down the group.
Rubidium is below potassium in Group 1.
Rubidium an... show full transcript
Worked Solution & Example Answer:This is about groups in the periodic table - AQA - GCSE Chemistry - Question 5 - 2022 - Paper 1
Step 1
Predict one observation you would see that shows that rubidium is more reactive than potassium.
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Answer
Rubidium produces more vigorous bubbling when added to water compared to potassium.
Step 2
Explain why rubidium is more reactive than potassium.
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Answer
Rubidium has a larger atomic radius than potassium, meaning the outer electron is further from the nucleus. This results in weaker electrostatic attraction between the outer electron and the nucleus. Additionally, rubidium has more electron shells, which provides increased shielding. As a result, rubidium loses its outer electron more easily than potassium, making it more reactive.
Step 3
Complete the equation for the reaction of rubidium with water.
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Answer
The balanced equation is:
ightarrow 2 ext{RbOH} + ext{H}_2$$
Step 4
Which is a correct statement about the noble gases?
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Answer
The noble gases have boiling points that increase going down the group.
Step 5
Calculate the relative atomic mass (Ar) of neon.
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Answer
To calculate the relative atomic mass of neon, use the formula:
Ar=100(90.48×20)+(0.27×21)+(9.25×22)
Calculating this gives:
Ar=100(1809.6)+(5.67)+(203.5)=20.1872
Rounding to three significant figures gives: 20.2.
