↪ About seventy five percent of the elements of the periodic table are metals.
↪ Elements of the periodic table are not classified on the basis of metals, metalloids and nonmetals.
↪ But division of elements of the periodic table into s, p, d and f blocks, the most electropositive metals are found to be grouped in s block (except H, a nonmetal), highly tensile and hard metals in d and I blocks, some poor metal, a few semi metals (metalloids) and rest of the elements as non metals in p block.
↪ They are solids (except Hg), lustrous, malleable, ductile and good conductor of electricity having atomic electrical conductivity greater than 10-3scm-4mol-1 which decreases with the increase of temperature.
↪ Metal oxides possessing their group oxidation number are basic in general.
↪ They are dull solids, not malleable and ductile e.g., B, Si, Ge, As, etc.
↪ They are poor electrical conductor and have atomic electrical conductivity less than 10-3s cm-4mol-1 and greater than 10-5 scm-4mol-1 approximately.
↪ They increase conductivity with the rise of temperature and presence of impurities. They possess properties partly of metals and partly of non metals and so they are called semi metals.
↪ They form amphoteric oxides.
⁕ Non metals
↪ They are gases, solids and bromine is the only liquid non metal.
↪ They are not malleable and ductile and bad conductor of electricity and have atomic electrical conductivity less than 10-10s cm-4mol-1.
↪ They form mostly acidic oxides and a few NO, CO, H2O are neutral.
Differences between Metals, Metalloids and Non Metals
|Behavior||Show metallic behavior||Both metallic and non metallic||Don't show metallic behavior|
|Periodic table position||Left side||Middle||Right side|
|Blocks||s, p, d and f blocks||p block||s and p blocks|
|Appearance||Shiny||May be shiny or dull||Dull|
|Electronegativity||Low||Neither too low nor too high||High|