Science: Metals and Non-Metals: Physical Properties of Metals and Non-Metals (For CBSE, ICSE, IAS, NET, NRA 2022)

Get unlimited access to the best preparation resource for CBSE/Class-10 : get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-10.

  • Elements which donate one or more electrons are metals and elements which gain one or more electrons are non-metals.
  • Transfer of electrons is done in order to complete octet in the outermost shell of electrons. There is also third type of elements showing properties of both metals and nonmetals known as metalloids.

Physical Properties of Metals and Non-Metals

Physical Properties of Metals and Non-Metals
Physical PropertiesMetalsNon-Metals
Malleability and DuctilityMetals are malleable. They can be beaten into thin sheets. They are also ductile and can be drawn into wire (except a few metals like Na, K etc.)Non-metals are neither malleable nor ductile. For e. g. coal, (carbon) and Sulphur
Metallic LustreAll the metals show metallic lustre.They do not show any metallic lustre.
HardnessMetals are generally hardNon-metals are soft in comparison to metals
Physical stateThey exist in solid and liquid statesNon-metals exist in solid, liquid and gaseous states.
SonorousMetals are sonorous and produce Characteristics metallic sound when struck (e. g. school bell)They are non-sonorous
DensityHigh densityLow density
Electrical conductivityGood electricity of electricityBad conductor of electricity

Chemicals Properties of Metals

Metals are electropositive in nature. They generally have 1,2 or 3 electrons in their valence shells and readily lose these electrons to form positively charged ions

These cations are stable as they acquire noble gas configuration after losing the valence shell electrons.

Reaction of Metals with Oxygen

Most of the metals react with oxygen and form oxides. The reaction may take place without heating as in sodium, calcium or potassium, while some metals react with oxygen on heating to form oxides.

4Na (s) + O2 (g) 2Na2O (s)

Mg (s) + O2 (g) 2MgO (s)

4Al (s) + 3O2 (g) 2Al2O3 (s)

Reaction of Metals with Acids

Metals react with common acids like dilute HCl and dilute H2SO4 with evolution of H2. The reaction of Mg ribbon with dil. HCl is represented in Fig. 27.1 below.

Mg (s) + 2HCl (aq) ⇾ MgCl2 (aq) + H2 (g)

Zn (s) + H2SO4 (aq) ⇾ ZnSO4 (aq) + H2

Reaction of Metals with Water

Many metals react with water to form hydroxides. Hydroxides are basic in nature. Sodium and potassium react with cold water.

2Na (s) + 2H2O (l) ⇾ 2NaOH (aq) + H2 (g)

2K (s) + 2H2O (l) ⇾ 2KOH (aq) + H2 (g)

Reaction of Metals with Common Bases

Some metals like aluminum and zinc react with common bases.

Sn (s) + 2NaOH (aq) + H2O (l) ⇾ Na2SnO3 sodium stannate

Corrosion

  • You must have seen a green layer over old copper coin. This green layer is due to oxidation leading to formation of copper oxide which is finally converted to basic copper carbonate on its surface due to its oxidation. All these processes of oxidation of metals are known as Corrosion.
  • Corrosion leads to the destruction of metal surface by the action of air and moisture the corrosion word is used for oxidation of different metals but in case of corrosion of iron we use specifically term rusting. . When iron reacts with oxygen it produce brown powder called rust which is chemically hydrated ferric oxide.

4Fe (s) + xH2O + 3O2 ⇾ 2Fe2O3. xH2O Brown Rust

For rusting of iron, two important conditions are required:

  • Presence of moisture
  • Presence of oxygen

Developed by: