Let`s sort the trashes
into recycling bins
What are the "building blocks" that make up the things around us?
How will these "building blocks" form different things?
The construction of light aircraft body
that is able to withstand extreme stress.
Chemical composition is the
chemical components
that make up a substance
The properties of mixture of metals are unlike the properties of pure aluminium
Element
Non- element
Compound
Mixture
CHEMICAL COMPOSITION OF MATTER
What are Elements?
Matter in its simplest form is called an element
The names of elements
are represented
by chemical symbols
Elements that are arranged
in the same horizontal row
belong to the same period.
As we move from
left to right
of a period,
the properties of elements
gradually change from
those of metals
to those non - metals
Elements that are arranged in
the same vertical column
belong to the same group.
Elements in the same group
have similar chemical properties
Metals
Non - metals
An element is a substance that cannot
be broken down into
two or more simpler substances
by chemical methods
H O
2H
O
2
Broken down
Non - element
Element
Element
Elements
Metals
Non -metals
What are compounds?
Praised as a potential model for green cars,
the exhaust of the cars only releases water.
Gas
Liquid
A compound is a subtance that is made up of two or more different elements chemically combined
PROPERTIES OF COMPOUNDS
combined
combined
combined
The properties of a compound are usually different from the elements it is made up of
The elements that make up a compound are always combined in a fixed proportion by mass
A compound cannot be broken down by physical methods. This is because a compound is made up of different elements that are chemical combined
What are mixtures?
The health supplements
Each pill contains a mixture
of these compounds and elements
A mixture consists of two or more
different substances
that are mixed, but not
chemically combined
inhaled air
exhaled air
Milk is a mixture of compounds
such as proteins and fats
An axample is inhaled air contains more oxygen
and less carbon dioxide than exhaled air
The substances that make up a mixture:
Elements
Compounds
Both elements and compounds
The components of a mixture may or may not be of the same state of matter
A Liquid -liquid mixture
ethanoic acid and water
A solid - liquid mixture
sugar in water
PROPERTIES OF MIXTURES
A mixture has the properties of the substances
it is made up of
The components of mixtures are not
mixed in any fixed proportion
AIR
When a mixture is formed,
no chemical reaction occurs.
Hence, a mixture can be seperated
easily by physical method
WHAT ARE SOLUTION? (HOMOGENIOUS)
The solute (e.g.salt) is the substance that dissolves in a solvent
The solvent (e.g water) is the subtance that dissolves the solute
The solution (e.g salt water) is the mixture of the solute and the solvent
Step 1. When the solute mixes with the solvent,
the solvent particles surround the solute particles
Step 2. The solute particles disperse
among the solvent particles
Step 3. Hence, when we look at a solution, we cannot distinguish betweeen the solute and the solvent
Carbon dioxide is dissolved in sugar solution
to make carbonated drinks
Soda water
Syrup
Salt solution
Syrup is dissolved in water to make drinks
Salt or sugar are dissolved in liquids when we cook
Dyes
Dyes are dissolved in water to produce colourful fabric dyes
Perfume
Oil from plants and flowers are dissolved in alcohol to produce perfumes
Leather
Some types of compounds are dissolved in organic (carbon -containing) solvents to make a waterproof layer for shoes
WHAT ARE SUSPENSIONS? (HETEROGENEOUS)
A suspension is a mixture in which insoluble substances are suspended in a liquid or gas
Antibiotics contain tiny solids
that settle to the bottom of
the container after some time
Orange juic conatins pulp,
which does not dissolve in the liquid
Drain water contains dirt
and other insoluble substances
Factor that affect solubility
What is solubility?
Solubility is the ability of a solute to disolve in a solvent
Nature of the solvent
Nature of the solute
Temperature
What is the rate of dissolving?
The rate of dissolving is the amount of solute that dissolves in a fixed volume of solvent,
given a fixed amount of time
FACTORS THAT AFECT HOW FAST A SOLUTE DISSOLVES
Temperature of the solvent
Size of solute particles
Rate of stirring
FACTORS THAT AFFECT HOW FAST A SOLUTE DISSOLVES