Differentiate between metals and non-metals on the basis of chemical properties.
1. Property: Electrochemical character
Metals : Metals are electropositive in nature, i.e. they lose electrons to form positively charged ions.
For example,
Na – e– ➝ Na+
Mg – 2e– ➝ Mg2+
Non-metals: Non-metals are electronegative in nature i.e. they accept electrons to form negatively charged ions.
For example,
O + 2e– ➝ O2
Cl + e– ➝ Cl–
2. Property: Nature of oxide
Metals : They form basic oxides and if soluble in water give alkaline solution. For example,
2Ca + O2 ➝ 2CaO
2CaO+2H2O⇌2Ca(OH)2
Non-metals: They form acidic or neutral oxides. When combined with water, they from acids. For example,
CO2 + H2O ⇌ H2cO3
N2O5 + H2O ⇌ 2HNO3
3. Property: Discharge of ions
Metals : On electrolysis, cations are discharged at the cathode.
Non-metals: On electrolysis, anions are discharged at the anode.
4. Property: Reaction with water/steam
Metals : Reactive metals like K, Na, Ca Al,
Fe displace hydrogen from water or steam.
Non-metals: They, generally, do not react with water.
5. Property: Reaction with dilute adds
Metals : They can displace hydrogen from acids and so form salts.
Zn + 2HCl(dil.) ➝ ZnCl2+ H2
Exception: Nitric acid (HNO3)
Non-metals: They do not react with dilute acids and hence do not displace hydrogen from acid.
6. Property: Oxidising/reducing behaviours
Metals : They act as reducing agents, i.e. they donate electrons.
Non-metals: They act as oxidising agents, i.e. they accept electrons.