2020 P1 Q3 - Determine Charge from Proton, Neutron and Electron Number

Let's take a look at 2020 A Levels H2 Chemistry Paper 1 Question 3.

2020 p1 q3 question

We are required to determine this unknown ion by deducing the proton, neutron and electron number.

We know that atomic or proton number is from 84 to 87. Let's find out what these elements are.

2020 p1 q3 elements atomic number 84 to 87

Now we can figure out the proton number, neutron number, electron number and charge of each element:
- proton number is the same as atomic number
- neutron number is nucleon number 217 minus proton number
- electron number is neutron number minus 50
- charge of ion is proton number less electron number

2020 p1 q3 determine neutron electron number and charge

From the calculations we will have the following ions: Po+, At3+, Rn5+, Fr7+.

We can now compare with the options and see which is consistent.

2020 p1 q3 answer

Option B with At3+ should be the correct answer.

Topic: Atomic Structure, Physical Chemistry, A Level Chemistry, Singapore

Back to list of questions for 2020 A Level H2 Chemistry Paper 1.

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