Metals and Non-Metals | Physical and Chemical properties of Metals and Non-Metals | Reaction of Metal and Non Metals with Air

 

Metals and Non- Metals full explaination

Class 10 Science

Chapter 3 - Metals and non metals

Element: Is a substance that can’t be broken into more simpler substances. Elements are classified into different categories:

-: Metals :-

Metals

Metals are those elements which have 1,2 or 3 valence electrons in their valence shell.

Example : atomic no. of Na =11

Electronic confugration =2,8,1

They always loose electrons to form electropositive ions.

Na – 1electron ------Na +

:- Non Metals :-

Non-Metals

-> Non metals are those elements which have 4,5,6 or 7 valence electrons in their valence shell and they always gain electrons to form electronegative ions.

Cl(17) – 1 electron --------Cl-

Electronic Configuration = 2,8,7

Video Explanation of Lesson Metals and Non-Metals

II) Physical Properties Of Metals and Non Metals

1. malleability: process of beating into thin sheets

Metals :are malleable. Gold and silver is the most malleable metals.

Malleability

Non metals :non malleable because they are brittle

2. ductility: process of drawing into thin wires

Metals:ductile

Ductility

:- Gold is the most Ductile metal. About 2 km length of wire can be drawn from one gram of gold.

Non metals: nonductile because they are brittle

3. Electrical Conductivity And Thermal Conductivity:

Electrical conductivity

Metals: good conductor of heat and electricity because of free mobile electrons in it.

-> Best conductor of Heat are silver and Copper.

Non metals: poor conductor of heat and electricity.

4. lustre: shine 

Metallic lustre

Metals: lustrous

Non metals: non lustrous

5. Hardness:

Metals: hard

Non metals: soft

6. physical state:

Metals: solid at room temperature

Non metal: can be solid, liquid or gaseous

7. melting and boiling point:

Metals :high m.pt and b.pt

Non metals: low m.pt and b.pt

8. Sonority: when 

Sonorous 

Metals:sonorous

Non metal:non sonorous

*Chemical properties of metals and non metals

1) Reaction With Air 

Reaction of metal with air

Metals react with oxygen to form metal oxide

metal +oxygen → metal oxide

Na + O2 -------->  Na2O

Mg + O2 ---------->  MgO

If we notice the nature of oxides the Metal oxides are basic in nature, i.e., they turn red litmus blue but some metal oxides proved to be amphoteric (i.e they have acidic and basic character). For example aluminium oxide and zinc oxide.

We can show their amphoteric nature by reacting them with acid and base i.e.

amphoteric nature

AL2O3 + NaOH --------->  NaAlO2 +H2O

AL2O3 + HCl  -----------> AlCl3+ H2O

Order of reactivity with oxygen:Na>Mg>Zn>Fe>Cu

Sodium and potassium are stored in kerosene oil because when they come in contact with oxygen, they form respective oxides and the reaction is explosive. So, in order to avoid contact with air, it is stored in kerosene oil.

-> Non metals react with oxygen to form non metal oxide

Non Metal +Oxygen →Non Metal Oxide

C + O2 -----> CO2

N2 + O2 ------> NO2

-> If we notice about Nature of non metal oxides, they are acidic i.e., turn blue litmus red. But Some non metal oxides are neutral like water, carbon monoxide, etc.