The majority of elements are metals. In the periodic table:
Elements in group 1 and group 2 are metals. Atoms of group 1 elements have one electron in their outer shell, and atoms of group 2 elements have two electrons in their outer shell.
Some elements in groups 6 and 7, and all in group 0 (also known as group 8) are non-metals. Atoms of group 7 elements have seven electrons in their outer shell, and atoms of group 0 elements, except helium, have eight electrons in their outer shell.
The reactions of elements are related to the number of electrons in their outer shells:
Most elements are metals. In their chemical reactions, metals atoms lose electrons to form positive ions. For example:
Elements that do not form positive ions in their chemical reaction are non-metals.
Metal and non-metal elements have different physical properties:
The table shows some other differences in physical properties.
|Properties of a typical metal (when solid)||Properties of a typical non-metal (when solid)|
|Good conductor of electricity||Poor conductor of electricity|
|Good conductor of heat||Poor conductor of heat|
|High density||Low density|
|Malleable (can be hammered into different shapes)||Brittle (breaks easily)|
|Ductile (can be pulled into wires)||Brittle (breaks easily)|