This document discusses the classification of matter into pure substances and mixtures. It defines elements, compounds, and mixtures. Elements are the simplest form of matter and cannot be broken down further. Compounds are combinations of elements that have distinct properties. Mixtures maintain the properties of their components and can be separated physically. Mixtures include solutions, suspensions, and colloids, which differ based on the size of particles and whether they are homogeneous. The document provides examples and characteristics of each type of pure substance and mixture.

1. Is Matter Around Us Pure
Matter
Substance Mixtures
Elements Compounds
Metals Non-metals Metalloids

2. Substance
• A kind of matter that cannot be separated by
any physical process is called a substance.
• Eg. Sugar, iron, water, salt, etc. The
composition of the substance is same
throughout, even at molecular and atomic
level.
• Characteristics of substances –
1. Contains only one type of atoms & molecules
2. Perfectly homogenous
3. Has definite MP, BP and density.

3. Mixtures
• A form of matter in which 2 or more substances
are present in any proportion
• Homogenous or Heterogeneous
Eg. Kerosene, salt solution Sand+water, Uniform
in its composition salt+iron powder
and properties. Different comp
and properties
Characteristics of Mixtures –
1. 2 or more subs in any proportion
2. Shows properties of all constituents
3. No energy is absorbed or evolved to make mix

4. 4. Solutions are homo, rest mix are hetero
5. Components can be separated by simple
physical methods.
Elements
An element is the simplest form of matter which
cannot be split into simpler substances by any
chemical or physical method. (Antonie Laurent
Lavoisier)
Element is composed of atoms of the same kind
115 elements – 92 natural and 23 man-made
On basis of phy and chem properties elements r
classified into Metals eg. gold, silver, copper
Non-metals eg. hydrogen,oxygen,nitrogen
Metalloids eg. Boron, silicon, germanium.

5. Compounds
A compound is made up of 2 or more elements
combined chemically in a definite proportion by
mass.
All compounds r formed as a result of chemical
reaction hence called chemical compounds
Eg. Water is a compound made of hydrogen and
oxygen combined in the ratio of 2:1 by volume.

6. Mixture Compounds
• Except solutions all mix • Always homogeneous
r heterogeneous
• Components r in any • Components r in fixed
proportion proportion
• Properties of • Property of compound
components r is diff than components
properties of mix • Cannot be separated by
• Can be separated by simple phy method,
simple physical method need chem method to
separate
• No energy is evolved or • Involves evolution or
absorbed absorption of energy

7. Types of Mixtures
Solutions Suspensions Colloids
Solutions
A homogeneous mixture of 2 or more substances is
a solution.
The substance that is dissolved to obtain a solution
is called a solute.
The substance in which the solute is dissolved to
obtain a solution is called the solvent.
In general the component present in larger amount
in the solution is the solvent and the component
that is present in smaller amount in solution is
called the solute.

8. Eg. of solution
• Sugar in water ( liquid + solid )
• Ethyl alcohol in water ( liquid + liquid )
• Carbon-dioxide and water ( liquid + gas )
• Brass – 70% copper + 305 zinc ( solid +solid )
• Ornaments- gold + copper or silver ( “ )
Solutions in which water is the solvent is called
the Aqueous solutions. (salt solution)
Solutions obtained by dissolving solute in any
other solvent than water is called Nonaqueous
solution.(tincture iodine)

9. Concentration of solution
The quantity of solute dissolved in the given
mass or volume of the solvent is called the
concentration of the solution.
Mass % of solute
= mass of solute/mass of solution X 100
Solve – To make a saturated solution, 36g of
sodium chloride is dissolved in 100g of water.
Find its concentration.
Conc = M of NaCl/M of solution X 100
= 36/36 + 100 X 100
= 36/136 X 100 = 26.5 %

10. Suspensions
A suspension is a heterogeneous mixture in which
very fine particles of solid are dispersed in any
medium. The fine particles remain suspended in the
medium. Eg. Muddy water, chalk + water, smoke
from chimney.
• Heterogeneous
• Particles are visible to eye or under simple
microscope.
• Particles have tendency to settle down
(sedimentation). But fine particles remain
suspended.
• Large particles can be separated by filtration.

11. Colloids
A heterogeneous mixture in which very fine particles
which can be observed only under powerful microscope
are dispersed in a continuous medium is called a colloid
or sols.
Eg. Milk, blood, jelly, gum, fog
• Heterogeneous
• particle size is btn 1 to 100nm. 1nm=1/1000000000m
• Colloids are unstable. Particles tend to come together
and settle.
• It shows Brownian Movement. (zig-zag)
• Tyndall effect – the scattering of light by the particles in
the colloid.
• Under electric current colloidal particles move to +ve
electrode. This is Electrophoresis.

12. Application of Colloids
• In our food. Eg milk, starch, proteins, jelly
• In medicines. Eg calcium and silver is used in
oral medicines and ointments.
• Raw natural rubber and clay is colloidal in
nature.
• Deltas at the sea are result of precipitation of
colloidal clay in the river water.