Why chemical reactions occur
I can explain chemical bonding in terms of the transfer or sharing of electrons.
Why chemical reactions occur
I can explain chemical bonding in terms of the transfer or sharing of electrons.
Lesson details
Key learning points
- There are five different types of substance: monatomic, simple covalent (molecules), giant covalent, ionic and metallic.
- The outer shell in most atoms can hold 8 electrons but, in hydrogen and helium, it can only hold 2 electrons.
- Most atoms increase their stability by forming bonds with other atoms so that they have a full outer shell of electrons.
- Some atoms will share electrons with other atoms to increase their stability.
- Some atoms will lose or gain electrons to increase stability forming cations or anions, respectfully.
Keywords
Molecule - A molecule is a particle consisting of a fixed number of (two or more) non-metal atoms covalently bonded together.
Noble gas configuration - When an atom has a full outer shell of electrons, it has a noble gas electron configuration.
Outer shell - The outer shell is the highest energy level in an atom and is usually the furthest from the nucleus.
Cation - A particle with a positive charge.
Anion - A particle with a negative charge.
Common misconception
Atoms react because they 'want' to gain a fuller outer shell of electrons – atoms don't have feelings! Monatomic means one atom and may be confused with the term element, which means one type of atom.
Take care with language and avoid personifying the atoms. Make sure that definitions and terms are used correctly.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
Relative mass of an atom, the total mass of its protons and neutrons.
Number of protons in the nucleus of an atom of an element.
The smallest particle of an element that can exist.
A group of atoms chemically bonded together.
Exit quiz
6 Questions
The arrangement of electrons in shells, in an atom or ion.
The highest energy level in an atom, contains electrons.
A particle with a positive charge.
A particle with a negative charge.
