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What are Non-metals? Define Non-metals
Non-metals are used as a term in
Periodic Chemistry when classifying the chemical elements. Each element can usually
be classified as a metal or a non-metal based on their general
Physical and Chemical Properties. Non-metals are any of the
non-metallic elements
within Groups 14,15 and 16 in the Periodic Table (see the List of
Non-metals). Non-metallic elements exist, at room temperature, in two of the
three States of Matter: Gases (such as oxygen) and
Solids (such as carbon).
What are Non-metals?
What elements are classified as Non-metals?
There is a great deal of variation among
this group of 7 elements classified as Non-Metals. Three of the elements are
gases and four are solids at normal room temperature. The Non-metals that
are are gases are Hydrogen, Nitrogen and Oxygen. The Non-metals that are are
solids are Carbon, Phosphorus, Selenium and Sulfer. The properties of
non-metals are therefore not universal or as consistent as the metals.
What are Non-metals? Common Properties of Solid Non-metals
Elements described as the solid Non-metals have low melting
points compared to the metals. They are poor conductors of
heat and electricity, they are brittle solids, not ductile
in their solid state - they cannot be rolled into wires or
pounded into sheets. They are usually dull and therefore
show no metallic luster and they do not reflect light. They
also have a low density.
Common properties of Solid Non-metals
The elements classed as solid Non-metals therefore have some
of the following
properties in common:
-
Poor
thermal conductors
-
Poor
electrical conductors
-
Low
Density
-
Dull, Brittle
solids
-
Little or
no metallic luster
-
High
ionization energies
-
High
electro-negativities
Non-metals List - Chemical Elements in the Periodic Table
The elements contained in
the classification of Non-metals list are as follows:
Elements classified as Non-metals
The 7 elements classified as "Non-metals" are located in Groups
14,15 and 16 of the Periodic Table. Solid Non-metals are not easily able
to conduct electricity or heat and do not reflect light.
Non-metallic elements are very brittle, and cannot be rolled into
wires or pounded into sheets. Non-metallic elements exist, at room
temperature, in two of the three states of matter : gases (such as
oxygen) and solids (such as carbon). |
