Ceist Eile

Ceist Eile is in development. Features, questions and prices may change while we refine it.

Subjects · Leaving Cert Chemistry

Leaving Cert Chemistry: Electronegativity

How often Electronegativity comes up on the Chemistry papers, every year it was asked, and questions to try.

HL Asked on 10 of the last 10 Higher Level papers, most recently in 2026. banker

OL Asked on 10 of the last 10 Ordinary Level papers, most recently in 2026. banker

June 2027 is the first exam on the new Chemistry course. These come from the 2016–2026 papers, so read them as a guide.

Electronegativity, Higher Level(6 marks)

Quick ones on Electronegativity.

(a)Element with a Pauling electronegativity value of 4.0?
  1. Oxygen
  2. Fluorine
  3. Chlorine
(b)Trend in electronegativity going down a group?
  1. Stays the same
  2. Increases
  3. Decreases
(c)Bond between two atoms of the same element, as in Cl2, is described as?
  1. Pure covalent (non-polar)
  2. Ionic (electron transfer)
  3. Polar covalent (partial charges)
Show the answers

(a) Fluorine

(b) Decreases

(c) Pure covalent (non-polar)

Your turn: Higher Level questions on Electronegativity.

Higher Level

Asked on 10 of the last 10 Higher Level papers, most recently in 2026. banker

Every paper, year by year

YearWhere it came up
2026Q5
2025Q10(a)
2024Q11(a)
2023Q5
2022Q10(b)
2021Q4(e)
2019Q11(a)
2018Q11(a)
2017Q11(b)
2016Q11(b)

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

More Electronegativity questions

Electronegativity, 3 marks

Definition of electronegativity?

  1. The energy needed to remove the outermost electron from a gaseous atom
  2. The charge carried by an ion in a lattice after electrons are transferred
  3. The attraction an atom in a molecule has for the shared pair of electrons in a bond
Show the answer

The attraction an atom in a molecule has for the shared pair of electrons in a bond

It is a comparative scale, not an energy. Pauling set fluorine at 4.0 and every other element is measured against it.

Electronegativity, 3 marks

Why is predicting bond type from electronegativity difference alone only a guide?

  1. It always gives exactly the right answer, so no other test is needed
  2. Bonding is a continuum, so a cut-off such as 1.7 is not a sharp boundary
  3. Electronegativity is exactly the same for every element in the same group
Show the answer

Bonding is a continuum, so a cut-off such as 1.7 is not a sharp boundary

Bonds range from pure covalent through polar covalent to ionic. Real properties, such as melting point and conductivity, are also needed.

Electronegativity, 3 marks

Values: K 0.82, Cs 0.79, F 3.98, I 2.66. Which pair would form the most ionic bond?

  1. Caesium and fluorine
  2. Potassium and iodine
  3. Caesium and iodine
Show the answer

Caesium and fluorine

The biggest difference gives the most ionic bond: Cs-F is 3.19, K-I is 1.84 and Cs-I is 1.87.

Ordinary Level

Asked on 10 of the last 10 Ordinary Level papers, most recently in 2026. banker

Every paper, year by year

YearWhere it came up
2026Q5
2025Q4(e)
2024Q5
2023Q4(e)
2022Q5
2021Q5
2019Q5
2018Q5
2017Q10(b)
2016Q5

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

More Electronegativity questions

Electronegativity, 2 marks

In a water molecule, which atom carries a partial negative charge?

  1. Hydrogen
  2. Both equally
  3. Oxygen
Show the answer

Oxygen

Oxygen is more electronegative than hydrogen, so it pulls the shared electrons closer and becomes slightly negative.

Electronegativity, 3 marks

Electronegativities: H = 2.20, Cl = 3.16. Bond type in HCl?

  1. Pure (non-polar) covalent
  2. Polar covalent
  3. Ionic
Show the answer

Polar covalent

The difference is 0.96. A difference between about 0.4 and 1.7 gives a polar covalent bond.

Electronegativity, 2 marks

Which of these is the least electronegative?

  1. Sodium
  2. Chlorine
  3. Oxygen
Show the answer

Sodium

Metals on the left of the table have low electronegativity. Sodium is 0.93, chlorine 3.16 and oxygen 3.44.

Other Chemistry topics

All of Leaving Cert Chemistry