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6 (a) An ion of element X can be represented as $$^{125}X^{2-}$$ This ion of element X has 54 electrons - Edexcel - GCSE Chemistry Combined Science - Question 6 - 2021 - Paper 1
Question 6
6 (a) An ion of element X can be represented as $$^{125}X^{2-}$$ This ion of element X has 54 electrons. Calculate the number of protons and the number of neutron... show full transcript
Worked Solution & Example Answer:6 (a) An ion of element X can be represented as $$^{125}X^{2-}$$ This ion of element X has 54 electrons - Edexcel - GCSE Chemistry Combined Science - Question 6 - 2021 - Paper 1
Step 1
Calculate the number of protons and the number of neutrons in this ion.
Answer
To find the number of protons, we need to consider that the number of electrons is 54. Since this ion has a 2- charge, the number of protons can be calculated as:
This indicates that element X has 56 protons.
To calculate the number of neutrons, we subtract the number of protons from the mass number:
Thus, the answers are:
- Number of protons: 56
- Number of neutrons: 69
Step 2
State, in terms of subatomic particles, how atoms of these isotopes are the same.
Answer
Isotopes of the same element have the same number of protons. This means that although they may differ in mass due to variations in the number of neutrons, their chemical properties remain similar as they contain the same number of protons and electrons.
Step 3
Calculate the relative atomic mass of silicon in this sample.
Answer
To calculate the relative atomic mass, we use the percentages of each isotope and their respective masses:
-
For silicon-28:
- Contribution = 28 * 0.92 = 25.76
-
For silicon-29:
- Contribution = 29 * 0.05 = 1.45
-
For silicon-30:
- Contribution = 30 * 0.03 = 0.90
Now, sum the contributions:
Thus, the relative atomic mass of silicon in this sample is:
- Relative atomic mass = 28.11