This question is about the periodic table - AQA - GCSE Chemistry Combined Science - Question 1 - 2021 - Paper 1
Question 1
This question is about the periodic table.
Figure 1 shows part of Mendeleev's version of the periodic table.
Which group of elements had not been discovered when M... show full transcript
Worked Solution & Example Answer:This question is about the periodic table - AQA - GCSE Chemistry Combined Science - Question 1 - 2021 - Paper 1
Step 1
Which group of elements had not been discovered when Mendeleev's version of the periodic table was published?
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Answer
The group of elements that had not been discovered is the noble gases (Group 0).
Step 2
Which model represents the plum pudding model?
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Answer
The plum pudding model is represented by option B.
Step 3
Which model resulted from Chadwick's experimental work?
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Answer
The model resulting from Chadwick's experimental work is option A.
Step 4
What is meant by 'isotopes'?
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Isotopes are atoms with the same number of protons (same atomic number) but with different numbers of neutrons. They can have different mass numbers.
Step 5
Calculate the relative atomic mass (A) of potassium.
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Answer
To calculate the relative atomic mass, use the formula:
A=100(39×93.1)+(41×6.9)
Calculating this yields:
A=100(3639.9)+(282.9)=39.138
Thus, the relative atomic mass of potassium, rounded to one decimal place, is 39.1.
