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Leaving Cert Physics & Chemistry: Bonding & electronegativity

How often Bonding & electronegativity 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 9 of the last 9 Ordinary Level papers, most recently in 2025. banker

Bonding & electronegativity, Higher Level(7 marks)

Quick ones on Bonding & electronegativity.

(a)Electronegativity is the relative attraction an atom has for…
  1. The protons in the nucleus of its own atom
  2. A shared pair of electrons in a covalent bond
  3. The free electrons in a metallic lattice
(b)What is an ionic bond?
  1. Attraction of positive ions to a sea of electrons
  2. A shared pair of electrons between two atoms
  3. Attraction between oppositely charged ions
(c)Electronegativities: Mg 1.3, O 3.4. The bonding in MgO is…
  1. Ionic
  2. Metallic
  3. Pure (non-polar) covalent
Show the answers

(a) A shared pair of electrons in a covalent bond

(b) Attraction between oppositely charged ions

(c) Ionic

Your turn: Higher Level questions on Bonding & electronegativity.

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(f), Q7(g)
2023Q8, Q12(b)
2022Q7(g), Q12(c)
2021Q7(c), Q7(d), Q12(c)
2019Q8, Q12(d)
2018Q7(e), Q7(h)
2017Q7(i), Q8
2016Q7(i), Q7(k)

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

More Bonding & electronegativity questions

Bonding & electronegativity, 2 marks

A covalent bond is…

  1. The attraction between oppositely charged ions
  2. The attraction of metal ions to free electrons
  3. A shared pair of electrons between two atoms
Show the answer

A shared pair of electrons between two atoms

In a covalent bond each atom usually gives one electron to a shared pair, held between the two nuclei. Ionic bonding is attraction between ions.

Bonding & electronegativity, 3 marks

Which bond is the most polar? (Electronegativity: H 2.2, F 4.0, Cl 3.2, I 2.7)

  1. H–I
  2. H–F
  3. H–Cl
Show the answer

H–F

Polarity depends on the electronegativity difference: H–F 1.8, H–Cl 1.0, H–I 0.5. The biggest difference gives the most polar bond.

Bonding & electronegativity, 2 marks

How does electronegativity change across a period, from left to right?

  1. It increases
  2. It decreases
  3. It stays the same
Show the answer

It increases

Across a period, nuclear charge rises and atoms get smaller, so they attract a shared pair of electrons more strongly. Fluorine, at the top right, is the most electronegative.

Ordinary Level

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

Every paper, year by year

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

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

More Bonding & electronegativity questions

Bonding & electronegativity, 2 marks

Electronegativity is?

  1. Energy needed to remove an electron from an atom
  2. Charge on the nucleus of an atom of the element
  3. Relative attraction of an atom for a shared electron pair
Show the answer

Relative attraction of an atom for a shared electron pair

Say relative and shared pair. Fluorine is the most electronegative element; values are in the Formulae and Tables booklet.

Bonding & electronegativity, 2 marks

An ionic bond is?

  1. Attraction between neutral molecules
  2. Attraction between oppositely charged ions
  3. A shared pair of electrons
Show the answer

Attraction between oppositely charged ions

One atom transfers electrons to another, making a positive and a negative ion that attract. Sodium gives an electron to chlorine to make Na+ and Cl-.

Bonding & electronegativity, 2 marks

A single covalent bond is formed by?

  1. Sharing one pair of electrons
  2. Transferring one electron
  3. Attraction between two ions
Show the answer

Sharing one pair of electrons

Each atom gives one electron to the shared pair, so both reach a full outer shell. H2 and Cl2 have single covalent bonds.

Other Physics & Chemistry topics

All of Leaving Cert Physics & Chemistry