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CAIE IGCSE Chemistry Group Period and Electron Shell Rules

CAIE IGCSE Chemistry Group Period and Electron Shell Rules
Cambridge IGCSE Chemistry 0620 syllabus for exams in 2026, 2027 and 20282026–2028

Practise using electronic configurations to infer an element's group and period and recognising noble gases by their complete outer electron shells.

How this is tested

  • infer a Group I to VII number from the number of electrons in the atom's outer shell
  • infer the period from the number of occupied electron shells in the atom's configuration
  • recognise a noble gas from a complete outer shell and connect this arrangement with stability

Question 5

[Maximum number: 1]

The electronic configurations of two elements are given.
element L: 2,8,8,1
element M: 2,8,4

Which row identifies the group number and the period number for element L and element M ?

group number

period number

group number

period number

I

4

IV

3

I

4

III

4

IV

1

III

4

IV

1

IV

3