Electronic configurations and the periodic table
4 marks · NormalThe table shows the electronic configurations and Periodic Table positions for four elements.
| Element | Electronic configuration | Group | Period |
|---|---|---|---|
| A | 2,8,4 | ||
| B | 2,8,8,1 | ||
| C | 2,7 | ||
| D | 2,8,5 |
Complete the table by entering the group and period for each element.
Which element is in the same group as carbon? Give a reason for your answer.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) — · must show Element A: Group 4, Period 3, Element B: Group 1, Period 4, Element C: Group 7, Period 2, Element D: Group 5, Period 3
(b) Element A, because both have 4 electrons in their outer shell.
Common mistakes: Mixing up shells for groups
Show mark scheme and worked solution
Marking points
A1 (a) · 2 marks · Both group and period correct for each element (1/2 mark for each correct row: group AND period correct).
B1 (b) · 1 mark · Identifies Element A is in same group as carbon.
B2 (b) · 1 mark · Correct reason: both have 4 electrons in their outer shell.
Worked solution
| Element | Electronic configuration | Group | Period |
|---|---|---|---|
| A | 2,8,4 | 4 | 3 |
| B | 2,8,8,1 | 1 | 4 |
| C | 2,7 | 7 | 2 |
| D | 2,8,5 | 5 | 3 |
Element A has 4 electrons in its outer shell (group 4). Carbon also has group 4.