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Leaving Cert Physics & Chemistry: Shapes of molecules

How often Shapes of molecules comes up on the Physics & Chemistry papers, every year it was asked, and questions to try.

HL Asked on 9 of the last 9 Higher Level papers, most recently in 2025. banker

OL Asked on 7 of the last 9 Ordinary Level papers, most recently in 2025. most years

Shapes of molecules, Higher Level(7 marks)

Quick ones on Shapes of molecules.

(a)Shape of an ammonia (NH3) molecule?
  1. Tetrahedral
  2. Pyramidal
  3. Planar triangular
(b)Water and methane both have 4 electron pairs round the central atom. Why is water's bond angle smaller?
  1. Hydrogen bonds pull the H atoms together
  2. Oxygen atoms are smaller than carbon atoms
  3. Lone pairs repel more strongly than bond pairs
(c)Shape of a BeCl2 molecule?
  1. Linear
  2. Pyramidal
  3. V-shaped
Show the answers

(a) Pyramidal

(b) Lone pairs repel more strongly than bond pairs

(c) Linear

Your turn: Higher Level questions on Shapes of molecules.

Higher Level

Asked on 9 of the last 9 Higher Level papers, most recently in 2025. banker

Every paper, year by year

YearWhere it came up
2025Q8
2024Q7(e)
2023Q12(b)
2022Q7(d), Q7(g)
2021Q12(c)
2019Q7(f)
2018Q12(d)
2017Q7(g), Q7(i)
2016Q7(i), Q12(d)

Links open the State Examinations Commission’s paper for that year.

Ordinary Level

Asked on 7 of the last 9 Ordinary Level papers, most recently in 2025. most years

Every paper, year by year

YearWhere it came up
2025Q12(b)
2024Q12(c)
2023Q7(f), Q8
2022Q12(b)
2021Q12(b)
2019Q12(c)
2018Not asked
2017Q12(c)
2016Not asked

Links open the State Examinations Commission’s paper for that year.

More Shapes of molecules questions

Shapes of molecules, 2 marks

Shape of a methane molecule, CH4?

  1. Linear
  2. Pyramidal
  3. Tetrahedral
Show the answer

Tetrahedral

Four bond pairs repel as far apart as possible, giving a tetrahedron with bond angles of 109.5°.

Shapes of molecules, 2 marks

Shape of a water molecule, H2O?

  1. Tetrahedral
  2. V-shaped (bent)
  3. Linear
Show the answer

V-shaped (bent)

Oxygen has 2 bond pairs and 2 lone pairs. The atoms form a V shape with a bond angle of about 104.5°.

Shapes of molecules, 2 marks

Shape of an ammonia molecule, NH3?

  1. Pyramidal
  2. Flat triangle
  3. Linear
Show the answer

Pyramidal

Nitrogen has 3 bond pairs and 1 lone pair. The lone pair pushes the three H atoms down into a pyramid, bond angle about 107°.

Other Physics & Chemistry topics

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