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An ion of element X can be represented as 125X²⁻ - Edexcel - GCSE Chemistry - Question 9 - 2021 - Paper 1
Question 9
An ion of element X can be represented as 125X²⁻. This ion of element X has 54 electrons. Calculate the number of protons and the number of neutrons in this ion... show full transcript
Worked Solution & Example Answer:An ion of element X can be represented as 125X²⁻ - Edexcel - GCSE Chemistry - Question 9 - 2021 - Paper 1
Step 1
Calculate the number of protons
Answer
The number of protons in an atom is equal to the atomic number. Given that the ion has a charge of 2- and contains 54 electrons, we can determine the number of protons:
Number of protons = Number of electrons + Charge = 54 + 2 = 56. Therefore, the number of protons is 52.
Step 2
Calculate the number of neutrons
Answer
The number of neutrons can be calculated by subtracting the number of protons from the mass number. The mass number (A) is 125. Using the formula:
Number of neutrons = Mass number - Number of protons Number of neutrons = 125 - 52 = 73. Therefore, the number of neutrons is 73.
Step 3
Step 4
Calculate the relative atomic mass of silicon in this sample
Answer
To calculate the relative atomic mass, we will use the weighted average based on the percentage of each isotope:
Total mass of 100 atoms = (92 imes 28) + (5 imes 29) + (3 imes 30) = 2576 + 145 + 90 = 2811.
Relative atomic mass = Total mass / Total number of atoms = 2811 / 100 = 28.11. Therefore, the relative atomic mass of silicon in this sample is 28.11.