Periodicity qp

Question 1

This question is about atomic structure.
(a) There is a general trend for an increase in ionisation energy across Period
3. Give one example of an element that deviates from this trend.
Explain why this deviation occurs.
Element
Explanation

Answer 1

Aluminium / Al

(Outer) electron in (3)p orbital / sub-shell (level)

(3p) higher in energy / slightly more shielded (than 3s) /
slightly further away (than 3s)

or
OR
Sulfur / S

(Outer) electrons in (3)p orbital begin to pair

Repel