Okuzeka
Chemistry vocabulary · Atoms and the Periodic Table

Valence electron

Meaning in chemistry, with examples

nounCore term

In chemistry, valence electron means: An electron in the outermost shell of an atom. These outer electrons take part in bonding and largely decide how an element reacts.

In Turkish: değerlik elektronu

How it is used

Used when you draw Lewis structures and explain why elements bond the way they do. Elements in the same main group have the same number of valence electrons: carbon has four, the halogens have seven.

Example sentences

  1. Nitrogen has five valence electrons and usually forms three bonds.

  2. Count the valence electrons before you draw the Lewis structure.

Common collocations

  • number of valence electrons
  • share valence electrons
  • valence shell
  • outer electrons
  • electronA tiny particle with a negative charge that moves around the nucleus of an atom. Chemical bonds and reactions are mostly about how these particles are shared or transferred.
  • electron configurationThe way an atom's electrons are arranged in shells and orbitals, written for example as 1s² 2s² 2p⁶ 3s¹ for sodium.
  • Lewis structureA drawing of a molecule or ion that shows its atoms, the bonds between them as lines, and the lone pairs of valence electrons as dots.
  • covalent bondA chemical bond in which two atoms share one or more pairs of electrons. It usually forms between nonmetal atoms, as in H₂, H₂O and CH₄.
  • periodic tableA chart that arranges all known elements in order of atomic number, in rows called periods and columns called groups. Elements in the same group behave in similar ways.

More terms: Atoms and the Periodic Table

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: