METALS Everything to LEFT side of the red 'staircase' (below image) is considered to be a metal.
NON-METALS Everything to the RIGHT of the red 'staircase' (in the image above) is considered to be a non-metal EXCEPT for the elements that touch the top of the red line which includes B, Si, As, Te, and At. The non-metal section of the periodic table includes the diatomic elements and H, hydrogen. Non-metals are the complete opposite of metals because they:
do NOT conduct heat and electricity well.
are NOT ductile.
are NOT malleable .
GAIN electrons rather than losing them like metals.
most of the non-metals are even liquids.
These elements are considered to be metals because:
they are solids (only exception is mercury, Hg, as a liquid).
shiny, good conductors of heat and electricity.
ductile - able to be strained into thin wires.
malleable - can be easily hammered into very thin sheets.
However, all these metals lose electrons easily which means that the metals have low ionization.
TRANSITION METALS The transition metals in the periodic table consist of 38 elements between groups 3-12. Like all metals, these 38 elements conduct heat and electricity. They have high melting and boiling points because of their ability to bond so well, however, group 12 has lower levels of boiling and melting points since the elements in this group mainly have full valence shells. Transition metals all have different charges, some even have 2, for example, Lead (Pb) has the charges 2+ and 4+.
METALLOIDS Metalloids that border the 'staircase' are the elements in yellow as seen above. The reason they are called 'metalloids' is because they contain properties of both metals AND non-metals. They are partial conductors of electricity.