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Metals and non-metals

Metals in the periodic table are highlighted in purple.
Metals in the periodic table are highlighted in purple.

Metals are elements that tend to lose valence electrons and become cations in ionic bonds. Metal atoms generally have fewer than four valence electrons.

Metals are found on the left of the dividing line in the periodic table.

Metallic character refers to the ability of an element to lose valence electrons. Atoms with more metallic character lose their valence electrons more easily than atoms with less metallic character.

Metal atoms with lower group numbers (located further left on the periodic table) tend to have a more metallic character than those with higher group numbers.

Metal atoms from lower-numbered groups lose their valence electrons more easily because they have fewer valence electrons to lose.

More metallic atoms are generally more reactive than less metallic atoms.

Magnesium ($$\ce{Mg}$$) (group 2) is more reactive than aluminium ($$\ce{Al}$$) (group 3) because magnesium loses its valence electrons more easily.

Non-metals in the periodic table are highlighted in green.
Non-metals in the periodic table are highlighted in green.

Non-metals are elements that generally have between four and eight valence electrons. These atoms gain electrons to become anions in ionic bonds.

These elements (except for hydrogen) are found on the left of the dividing line on the periodic table. Hydrogen can form either anions or cations.

Atoms of non-metals in higher group numbers tend to be more reactive than atoms of non-metals with lower group numbers.

Atoms of higher group numbers gain electrons more easily because they require fewer electrons to form a stable electron configuration.

Group 0 (noble gases) is an exception to this because these atoms usually do not react.

Group 7 elements (halogens) tend to be the most reactive non-metals because their atoms each need to gain one valence electron.

Fluorine ($$\ce{F}$$) (group 7) is more reactive than oxygen ($$\ce{O}$$) (group 6) because fluorine only has to obtain one electron while oxygen has to obtain two.

Metalloids in the periodic table are highlighted in orange.
Metalloids in the periodic table are highlighted in orange.

Metalloids are elements that have properties in between those of metals and non-metals.

Metalloids have a shiny appearance like metals. Unlike metals, they do not form basic oxides and form slightly acidic (similar to non-metals) or amphoteric oxides instead.

Metalloid elements are found along the dividing line on the periodic table.

On the periodic table, metals and non-metals are separated by a divide that moves downwards and to the right. Metals are found to the left of this divide while non-metals are found to the right of it.

Metalloids are found along this divide between metals and non-metals.

Antimony $$(\ce{Sb})$$ is a metalloid that has a silvery grey appearance.
Antimony $$(\ce{Sb})$$ is a metalloid that has a silvery grey appearance.