First 249 words of the document:
Ions are electrically
charged particles formed when atoms lose or gain electrons. They have
the same electronic structures as noble gases.
Metal atoms form positive ions, while non-metal atoms form negative
ions. The strong electrostatic forces of attraction between oppositely
charged ions are called ionic bonds.
Ionic compounds have high melting and boiling points.
How ions form
Ions are electrically charged particles formed when atoms lose or gain electrons.
This loss or gain leaves a complete highest energy level, so the electronic
structure of an ion is the same as that of a noble gas - such as a helium, neon
Metal atoms and non-metal atoms go in opposite directions when they ionise:
Metal atoms lose the electron, or electrons, in their highest energy level
and become positively charged ions.
Non-metal atoms gain an electron, or electrons, from another atom
tobecome negatively charged ions.
Positively charged sodium and
Negatively charged oxide and
How many charges?
There is a quick way to work out what the charge on an ion should be:
the number of charges on an ion formed by a metal is equal to the group
number of the metal
the number of charges on an ion formed by a non-metal is equal to the group
number minus eight
hydrogen forms H+ ions