Ions
Science: KS3, topic 2.6.1
Ions
Ions are particles that have a charge. They are created when an atom or molecule gains or loses electrons. Gaining electrons creates a negatively charged ion; losing electrons creates a positively charged ion.
Positive ions (cations)
- Positive ions are usually created when an atom or molecule loses electrons.
- Positive ions are also called cations.
- The metals in Group 1 and 2 can easily lose electrons to become positively charged ions.
Negative ions (anions)
- Negative ions are usually created when an atom or molecule gains electrons.
- Negative ions are also called anions.
- The non-metals in Group 7 are most likely to gain electrons to fill up their electron shell and become negatively charged.
Ions containing multiple elements
- Ions can be made up of:
- 1 atom (e.g. F-).
- Combinations of atoms with an overall charge (e.g. SO42-).
Test yourself on Ions
Calcium is in group 2 of the periodic table. What happens to a calcium atom when it becomes an ion?
Select the correct statement about forming ions
If an atom loses electrons, what charge does the resulting ion have?
An atom loses electrons to form an ion. What is this type of ion called?