IB skill practice

Write electron configurations for atoms and ions

Paper 1, Paper 2 5 marks Difficulty 4

Valence electrons from shell arrangement

An atom in a food chemistry audit has atomic number \(16\). For the first 18 elements, determine the number of outer-shell electrons. Enter the answer and choose the interpretation that matches the chemistry.

Worked practice: chemistry evidence and answer

Use the chemical evidence first, then enter the result and interpretation that match it.