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CHEMISTRY METALS AND NON-METALS

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Properties of Metals and Non-Metals

Physical Properties of Metals and Non-Metals

Metals Non-metals

Physical state Metals are solids and heavy,

except mercury and gallium which

are liquid at room temperature.

Most of the non-metals are gases at

room temperature. A few are solids

such as sulphur and iodine. Bromine

is the only non-metal which is liquid at

room temperature.

Lustre

Metals in their pure state have a

shining surface. This property is

called metallic lustre. Metals can

be polished to produce a high

reflective surface.

Non-metals do not have metallic lustre

because most of them are in the

gaseous state. However, silicon,

iodine and graphite have metallic

lustre.

Hardness

Metals are generally hard, with

the exception of sodium,

potassium and lead which are soft

and can be easily cut with a knife.

Non-metals which are solids are hard

but brittle in nature. However, diamond

which is an allotrope of carbon is the

hardest naturally occurring substance.

Colour

Metals are grey or silver in colour,

except copper which is reddish

brown and gold which is yellow.

Non-metals occur in various colours.

Iodine is purple, sulphur is yellow and

chlorine gas is greenish yellow.

Malleability

Metals have the ability to

withstand hammering and can be

made into thin sheets. This

property is called malleability.

Non-metals cannot be made into thin

sheets by hammering, i.e. they are not

malleable.

Ductility

The ability of metals to be drawn

into thin wires is called ductility.

Gold and silver are the most

ductile metals. It is observed that

one gram of gold can be drawn

into a wire with a length of 2

Non-metals cannot be drawn into

wires, i.e. they are not ductile.

Elements

Metals

E.g.: Gold, Copper

Non-metals

E.g.: Oxygen, Carbon

Metalloids

E.g.: Antimony, Silicon

Inert gas

E.g.: Helium, Argon



kilometres.

Thermal

conductivity

Metals are good conductors of

heat. Silver is the best conductor,

followed by copper and

aluminium. Because of this

property, cooking vessels are

made of copper and aluminium

metals. Lead is a poor conductor

of heat.

Non-metals do not conduct heat,

except diamond and graphite,

allotropes of carbon, are good

conductors of heat.

Electrical

conductivity

Metals are good conductors of

electricity. Electrical conductivity

of copper, aluminium and silver is

comparatively high.

Non-metals are non-conductors of

electricity. However, graphite, an

isotope of carbon, is a good conductor

of electricity.

Graphite is the only non-metal which

is used in electrochemical cells

because it is a good conductor of

electricity.

Sonority

Metals produce a ringing sound

when struck with a hard object.

This property of metals is known

as sonority, i.e. metals are

sonorous.

This property is made use of for

making wind chimes, metal bells

etc.

Non-metals produce a dull sound

when they are hit with some other

material. Thus, they are non-

sonorous.

Melting point and

boiling point

Melting and boiling points of

metals are very high. For

example, melting point of iron is

1539°C. However, mercury is a

metal which is liquid at room

temperature and sodium, gallium

and tin have low melting points.

Non-metals have low melting and

boiling points, except graphite which

has high melting and boiling points.

Tensile strength

Metals can resist strain without

breaking, i.e. they have high

tensile strength.

Non-metals have low tensile strength.

They are brittle and break easily on

application of strain.

Density

Density is a measure of mass per

unit volume of a substance.

Most of the metals have high

density, except sodium and

potassium which have low density

and float in water.

Non-metals have low density.



Chemical Properties of Metals and Non-Metals

Metals Non-metals

Electronic

configuration

Metals have 1, 2 or 3 valence

electrons.

Non-metals usually have 4, 5, 6 or 7

valence electrons.

Valency Metals are electropositive in nature

because they readily lose electrons

and form positively charged ions,

i.e. cations.

e → Na

+

Valency: +1

2 e → Mg

2+

Valency: +2

3e → Al

3+

Valency: +3

Non-metals are electronegative in

nature because they readily gain

electrons and form negatively

charged ions, i.e. anions.

Cl + e → Cl

Valency: −1

O + 2 e → Cl

Valency: −2

N + 3 e → Cl

Valency: −3

Oxidising/Reducing

nature

Metals lose electrons during a

chemical reaction; they are good

reducing agents.

Non-metals gain electrons during a

chemical reaction; they are good

oxidising agents.

Nature of oxides Oxides of metals are basic in

nature and dissolve in water to

form alkaline solutions.

Oxides of non-metals are acidic in

nature and dissolve in water to form

acidic solutions.

Reaction with

Acids

Metals do not usually react with H2.

Metals placed above hydrogen in

the activity series react with dil. HCl

and dil. H2SO4 to liberate H2 gas.

M + 2HCl MCl2 + H2

(dil.)

M + H2SO4 MSO4 + H2

(dil.)

Non-metals do not react with dilute

acids to liberate hydrogen.

Reaction with

chlorine

Metals react readily with Cl2 to form

chlorides.

Non-metals usually form chlorides,

which are volatile covalent liquids or

gases.

Reaction with water On the basis of reactivity, metals

react with water or steam to

produce hydroxides or oxides.

No such reaction occurs with non-

metals. [Exception: Cl2 dissolves in

water to form chlorine water which

contains hydrochloric acid.]



Chemical Reactions of Metals

Reaction of Metals with Oxygen

Almost all metals react with oxygen to form metal oxides.

Metal + Oxygen → Metal oxide

Sodium and potassium are most reactive and react with oxygen in the air at room temperature to

form oxides.

Most metallic oxides are insoluble in water, but some dissolve in water to form alkalis.

Magnesium does not react with oxygen at room temperature. However, on heating, it burns in air

with intense light and heat to form magnesium oxide.

On heating in air, copper combines with oxygen to form black copper (II) oxide.

Metal oxides are usually basic in nature, but oxides such as aluminium oxide and zinc oxide react

with both acids and bases to form salt and water. Hence, they are amphoteric in nature.

4Na + O2 → 2Na2O

4K + O2 → 2K2O

Na2O + H2O → 2NaOH

K2O + H2O → 2KOH

2Mg + O2 → 2MgO

2Cu + O2 → 2CuO

Al2O3 + 6HCl → 2AlCl3 + 3H2O

Al2O3+ 2NaOH → 2NaAlO2 + H2O (Sodium aluminate)



Reaction of Metals with Water Metals react with water and produce metal oxide with the release of hydrogen gas. However, all metals do

not react with water.

Metal oxides which are soluble in water dissolve to form hydroxide.

Metal + Water → Metal oxide + Hydrogen

Metal oxide + Water → Metal hydroxide

Metals such as sodium and potassium react vigorously with cold water to evolve hydrogen which

immediately catches fire producing a lot of heat.

Calcium reacts less vigorously with water and the heat evolved is not sufficient for hydrogen to catch

fire. Calcium starts floating in water when allowed to react with it.

Magnesium does not react with cold water but reacts with hot water to form magnesium hydroxide with

the evolution of hydrogen gas.

Metals such as aluminium, zinc and iron do not react with cold or hot water, but they react with steam

to form metal oxide and hydrogen.

2K + 2H2O → 2KOH + H2 +Heat

2Na + 2H2O → 2NaOH + H2 + Heat

Ca + 2H2O → Ca(OH)2 + H2

Mg + 2H2O → Mg(OH)2 + H2

2Al + 3H2O → Al2O3 + 3H2

3Fe+ 4H2O → Fe3O4+ 4H2

Aluminium oxide is amphoteric in nature, i.e. it can react with both

acids and bases.

Acid - Al2O3 + 6HCl → 2AlCl3 + 3H2O Base - Al2O3 + 2NaOH → 2NaAlO2 + H2O



Reactions of Metals with Acids Metals react with acids to form salt and hydrogen gas.

Metal + Acids → Salt + Hydrogen

Metals react with dilute hydrochloric acid to produce metal chloride and hydrogen gas. The reactivity

decreases in the order: Mg > Al> Zn > Fe.

Metals also react with sulphuric acid to form metal sulphate and hydrogen gas.

Metals also react with nitric acid, but hydrogen gas is not evolved, because nitric acid is a strong

oxidising agent. So, it oxidises the hydrogen to water and itself gets reduced to any nitrogen oxide.

However, magnesium and manganese react with dilute nitric acid to evolve hydrogen gas.

Mg + 2HCl → MgCl2 + H2 ↑

2Al + 6HCl → 2AlCl3 + 3H2 ↑

Zn + 2HCl → ZnCl2 + H2 ↑

Fe + 2HCl →FeCl2 + H2 ↑

Fe + H2SO4 → FeSO4 + H2 ↑

Zn + H2SO4 → ZnSO4 + H2 ↑

Mg + 2HNO3 → Mg(NO3)2 + H2 ↑

Mn + 6HNO3 → Mn(NO3)2 + H2 ↑



Chemical Reactions of Non-metals

Reaction of Non-metals with Oxygen Non-metals react with oxygen (air) on heating to form their respective oxides. Most of these oxides are

acidic in nature, and they turn moist red litmus paper blue and form salt and water with bases.

Non-metal + Oxygen → Non-metallic oxide

Carbon burns in oxygen to produce carbon dioxide.

i. Sulphur burns in oxygen to produce sulphur dioxide.

Reaction of Non-metals with Acids Non-metals do not react with dil. HCl or H2SO4.

However, they react with concentrated acids.

Reactivity Series (or Metal Activity Series) The arrangement of metals in the order of decreasing reactivities is called reactivity series of metals.

The most reactive metal potassium is placed at the top of the series, and the least reactive metal platinum

is placed at the bottom.

C + O2 + Heat → CO2

CO2 + 2NaOH → Na2CO3 + H2O

S + O2 + Heat → SO2

SO2 + 2KOH → K2SO3 + H2O

C + 2H2SO4 +Heat → CO2 + 2SO2 + 2H2O

S + 2H2SO4 → 3SO2 + 2H2O

P + 5HNO3 → H3PO4 + 5NO2 + H2O



Reactions of Metals with Solutions of other Metal Salts (Displacement Reaction)

A more reactive metal displaces a less reactive metal from its salt solution.

Metal A + Salt solution B → Salt solution A + Metal B

When an iron nail is placed in a copper sulphate solution, the blue colour of copper sulphate (CuSO4)

fades away slowly and reddish-brown copper metal is formed.

However, if a strip of copper metal is placed in iron (II) sulphate, then no reaction occurs because copper

is less reactive than iron and therefore cannot displace iron from iron (II) sulphate.

CuSO4(aq) + Fe(s) → FeSO4(aq) + Cu(s)

Hydrogen is included in the activity series of metals because like

metals, hydrogen also loses an electron and becomes positively

charged (H+) in most chemical reactions.



Occurrence of Metals

Free State

Gold and platinum are found exclusively in a free state because they are non-reactive elements.

Copper, mercury and silver are less reactive. Because of low reactivity, they occur in native or free

state.

Combined state

Most metals occur in combination with other substances. These metals are mostly reactive.

They mainly occur as oxides, sulphides, sulphates, carbonates and silicates.

properties of metals and non-metals - topperlearning

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