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Introduction to Metals, Metalloids and Non metals

↪ 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.

⁕ Metals

↪ 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.

⁕ Metalloids 

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

FeaturesMetalsMetalloidsNon Metals
BehaviorShow metallic behavior
Both metallic and non metallic
Don't show metallic behavior
Periodic table positionLeft side
MiddleRight side
Blockss, p, d and f blocksp blocks and p blocks
AppearanceShinyMay be shiny or dullDull
ElectronegativityLowNeither too low nor too highHigh
Malleability YesNoNo