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(a) A chlorine atom contains 17 electrons, 18 neutrons and 17 protons - Edexcel - GCSE Chemistry - Question 8 - 2018 - Paper 1
Question 8
(a) A chlorine atom contains 17 electrons, 18 neutrons and 17 protons. (i) State the mass number of this chlorine atom. (ii) Give the electronic configuration of t... show full transcript
Worked Solution & Example Answer:(a) A chlorine atom contains 17 electrons, 18 neutrons and 17 protons - Edexcel - GCSE Chemistry - Question 8 - 2018 - Paper 1
Step 1
State the mass number of this chlorine atom.
Answer
The mass number of a chlorine atom can be calculated by adding the number of protons and neutrons together. Since the chlorine atom has 17 protons and 18 neutrons, the mass number is given by:
Therefore, the mass number of this chlorine atom is 35.
Step 2
Give the electronic configuration of this chlorine atom.
Answer
The electronic configuration of a chlorine atom, which has 17 electrons, can be expressed in the following way:
This shows that there are 2 electrons in the first shell, 8 electrons in the second shell, and 7 electrons in the outer (third) shell.
Step 3
Describe what you would see if damp, blue litmus paper is placed into chlorine gas.
Answer
When damp, blue litmus paper is introduced to chlorine gas, the blue litmus will first turn pink and then bleach out to white. This reaction occurs because chlorine gas is a strong oxidizing agent and has the ability to react with the moisture in the litmus paper to create acidic conditions, indicating that it is acidic in nature.