MATTER AND SUBSTANCESMATTER AND SUBSTANCES

When we go sightseeing in a park,

we are surrounded by a variety of physical objects. There are variety materials such as trees, swings and slides. In addition, there are a variety of aquatic life in ocean and certainly fresh air in the park.

CHANGES OF STATE OF MATTER

Matter is anything that has mass and occupies space. The kinetic theory of matter states that:

Matter is made up of tiny and discrete particles. The particles are constantly vibrating , rotating or

moving freely. There are force of attraction and kinetic energy

between the particles. Particle have kinetic energy and are constantly

colliding into each other. The temperature increases the kinetic energy also

increases.

Kinetic theory

The characteristic of matter in the solid,

liquid and gas states

Properties of matter Solid Liquid Gas

Arrangement of particles

Closely arranged in an orderly manner at positions.

Not orderly arranged and there is space between the particles.

Not orderly arranged and particles are far away from one another.

Movement of particles Just vibrate and rotate at fixed positions.

Moving randomly within the liquid.

Move freely in all direction at high speed.

Forces of attraction between particles

Very strong Not very strong Very weak

Kinetic energy of the particles

Very low Moderate strong Very high

Density High Moderate Very low

Shape Fixed Fixed but Follows the shape of the container

Not fixed but follows the shape of container.

Volume Fixed Fixed Not fixed but follows the volume of the container

Compression Cannot compress Very difficult to compress

Easily compressed

Changes in state of matter

Sublimation

Sublimation

A change in state , involves the loss or

absorption of heat.

Melting

Melting point Occur at the melting point of a solid for ice it is 0ºc.

Heat is absorb causing the particles to vibrate faster and more vigorously.

The force attraction between the particles will lower and this causes the particles to move further apart and become a liquid.

Freezing

Opposite of melting at the freezing point, water freezes at 0ºc.

A liquid is cooled and heat is released from the liquid.

The kinetic energy decreased and the forces of attraction between the particles increases.

The particles get closer to one another and liquid freeze

Boiling

Happens at boiling point of a liquid for water it is 100ºC.

Liquid is heated to boiling, heat energy is absorbed and the kinetic energy between particle increased.

The liquid particles have higher kinetic energy to overcome the forces of attraction between the particles and turn into a liquid.

Condensation

Opposite of boiling When vapour(gas) is cooled,

heat is removed, kinetic energy between particle decreases.

Force attraction between molecules increase

The gas turns into liquid form.

Sublimation

In the process of sublimation, a solid changes directly to the gaseous state or a gas change directly to the solid state without going through the liquid state.

We know that matter consists

of tiny particles that are discrete. The particles are known as atoms. An atom is made up of three subatomic particles called electron, neutrons and electrons.

Atomic structure

Development of atomic model

1808, John Dalton-Daltons atomic theory 1897, joseph John Thomson- Discovered

electrons 1911, Rutherford-Discovered the model of

nucleus 1932, Sir James Chadwick- Discovered

neutrons in the nucleus 1932, Niels Bohr- proposed orbiting the

nucleus

There are three type of subatomic

particles in an atoms. I,e : protons, neutrons and electron.

Proton and neutrons make up the atomic form in the centre

AtomAtom circle around the nucleus at a high speed in fixed routes called electronselectrons

Subatomic particles

Properties

Electrons Protons Neutrons

Symbols ee pp nn

Location AroundAround the nucleus

In the centercenter

In the nucleus

The movement

Jump from one atom to another atom

Do not move

Do not Do not move

Charge Negative Positve Neutral

Relative mass

1/1840 1 1

The actual mass

9.107x10^-28

1.672x10^-24

1.67x10^-24

In nature all the atoms are

naturalnatural., ie: the number of protons is equal to the number of electrons. An atoms that accepts electrons will become negativenegative charged. An atom that loses electrons will become positivepositive charged.

Proton number and nucleon number

Proton Number•The proton number is the numbernumber of protons in the atoms

PROTON NUMBER = NUMBER OF PROTONS

Nucleon NumberThe nucleon number of an atom is the sumsum of protons and neutrons in the nucleus of the atom.

NUCLEON NUMBER = NUMBER OF PROTONS + NUMBER OF NEUTRONS.

•The atomic mass is nearly samesame to the mass of the protons and neutrons in the atomic nucleus as the mass of the atomatom is too small and can be ignored.

Atom Number of

nucleon (A)

Number of

Protons

(Z)

Number of

Electrons (=Z)

Number of

neutrons (A-Z=N)

Hydrogen

1 1 1

Helium 4 2 2Lithium 7 3 3Chlorin

e35 17 17

Examples:

Isotopes

Isotopes are elements that have the same number of protonsprotons but different number of neutronsneutrons.

Isotopes of the same element have the same chemicalchemical properties but different physicalphysical properties.

Oxygen has three isotopes, oxygen-16, oxygen-17, and oxygen-18. The proton number is 8 but three isotopes have different number of neutrons. neutrons.

All the elementelement must be classified and

arranged in a proper way. Scientist have arrangearrange these element based on their physical properties and chemical properties.

Dmitri Mendeleev ( father of the periodic table) had classified the elements according to accending order number of proton. number of proton.

Classification of element

The periodic table has 18 groups. The vertical column is called a group. All the elements in each group have same chemicalchemical

properties they have same number of proton in the outermost shell.

The horizontal rows in the periodic table are known as periodperiod.

There are 7 periods in the periodic table and the element of each period is arranged in ascending order of proton number from the left to the right.

All the elements that are in the same period have same number electronelectron in the outermost shell.

The groups and periodic table

GROUP

CONSISTS PROPERTIES

1 Alkali Metal Highly reactive

2 Earth alkali metal Highly reactive

17 Non metal (halogens) halogens

18 Noble gases Chemically stable and unreactive

3-13 Transition metal Hard, and shiny, good conductor of electricity.

Summary of information :

Metal : group 1,2, 13 and transition metal Metal : group 1,2, 13 and transition metal

Non-Metal : group 16,17,18

Non-Metal : group 16,17,18

The elementelement in the periodic table can be divided into

three main groups, namely metal, semi-metal , semi-metal and non-metals.

When moving across the period, the elements vary: Properties of physicalphysical – the elements change from

metals to non-metals StateState condition- the elements change from solid

to the gaseous state. Elements also change from being electric

conductivityconductivity to being electric insulator. The atomic size increasesincreases.

Importance of the periodic table

• helps us to study elements in an orderly and systematic approach.

• helps us to know the properties elements easily because the elements with similar properties are located in the same group.

• helps us to predict the properties and uses of an element by referring to the element’s location in the periodic table.

Matter consists of particles known as elementelement.

Element are substances that consist of atoms of one type only.

Metal substances made up of atoms held in place by strong forces of attraction called moleculesmolecules.

Most non-metal from molecules , a molecule consists of oneone or more atoms of the same type or different types which are chemically combined together.

Some metal combine with non-metal by …………. Of electrons to form ………….compounds.

Properties of substances based on the particles

present in them

An atom is the tiniesttiniest particle of an

element. Most metal made up of atoms of atomic atomic

substances substances type only and can exist on their own.

Atoms in metals are held by very strongstrong forces of attraction called metallic bond .

Atoms

A molecule is a particle that is made up of two

or more atoms that are combined together. There are two type of molecules;

Molecules that have two or more atoms of the same type.

Molecules that consist of different or more type of atoms.

Molecules

There are weak forces of attraction between the molecules which are known as attraction forces.

There are a group of solids known as …………….macromolecules which are held by very strong covalent bonds. Diamond and graphite are the best examples of covalent macromolecules which are…………..solids.

Ions

Physical property

Atomic Substance

Molecular Substance Ionic Substances

Physical state at room temperature

Solid Solid except mercury

Solid : IodineLiquid : WaterGas : Oxygen* Gas, liquid and solids for macromolecules

SolidSolid(crystalline)

Arrangement of particles

Packed very closely

Solid : PackedLiquid : Not packedNot packedGas : Far apart

Packed very closely

Forces of attraction between particles

Very strong through metallic bonding

Weak through attractionattraction forces

Very strong by charged charged bonding

Physical Properties

Melting point and boiling point

High High melting and boiling points

Low High High melting and boiling points

Electrical conductivity

conductivitconductivity y electricity in water or organic solvents

Does not Does not conduct conduct electricity in water but soluble in organic solvents

Conducts electricity in molten state

Solubility Does not Does not dissolve dissolve in anything

UndissolveUndissolve in water but soluble in organic solvents

dissolvedissolve in water but insoluble in organic solvents

There are many objects that are

made of metalmetal. What are these objects? Examples are screws, wrenches, keys, nails and many more. What about non metallic objects? Examples of non-metalnon-metal are paper, books, wooden desks, plastic cup and others.

Metals and non-metals

Physical properties

Metals Differences Non-metalsHave shiny surfaces

Luminosity Have dull surfaces

Ductile Ductility Not ductileEasily rolled or hammered into foils or thin sheets

Malleability Cannot be forged

High Tensile strength LowGood conductor of electricity

Electrical conductivity

Do not conduct electricity

except carbonGood conductor of heat

Heat conductivity Poor conductor of heat

High Melting point and boiling point

Low

High Density LowSolid (except mercury in liquid state)

State of matter at room

temperature

Solid, liquid, or gas

Metal Physical Property Use

Iron High tensile strength Railway tracks and framework for bridges

Aluminium

Light, good conductor of electricity and heat

Kitchen utensils and electric cables

Copper Ductile and malleable, good conductor of electricity and heat

Electrical wires

Tin Do not rust Electroplating of food cans

Gold Does not rust and is shiny

Jewellery

Lead Ductile, malleable Cable casing

Uses of metal & non-metal

Non-metal Physical Property Use

Carbon (graphite)

Soft and smooth, good conductor of electricity

Lead of pencils, used as the electrodes in electrolysis and in dry cell

Carbon (diamond)

Hard Drill bits for cutting stone

Neon gas and krypton

Poor conductor of heat

Lights used for billboards

Chlorine Acidic Used to kill germs in drinking water

Uses of non-metals

Diamonds are mostly

used to make

jewellery

Sulphur is ingredient in making paint

Sulphur is used to make

matchstick tips

Sulphur is used to make

matchstick tips

Characteristics of pure substances. pure substances do not contain any impurities. pure substances always have specific melting

(freezing) point and boiling point. for example : pure water boils at 100oC and ice

melts or freezes at 0oC at normal atmospheric pressure. pure iron melts at 1540oC and boils at 2800oC at normal atmospheric pressure.

Methods of purifying substances

any impurities added to a pure

substance will increase the boiling point or lower the freezing (or melting) point of that substance.

for example : water that is added with salt will boil at a temperature higher than 100oC and will freeze at a temperature lower than 0oC.

impurities can be separated from pure

substances. the process of separating impurities

form a substance is called purification. there are two methods of purification :

distillation crystallisation

Method of substance purification.

Methods of purification

Purification is a process of removing impurities from a substance.

The methods are:a) Filtration: process of separating solid from liquid

Mixture of solid and liquid

Filter paper

Residue (solid)

Filtrate (liquid)

b) Crystallisation : process of forming crystals from a liquid or gas- production of salt from sea water- production of pure solid copper(II)sulphate from its solution

Substance in crystal form

crystallisation is a purification method

carried out to obtain pure crystals from a saturated solution of the substances.

example : purification of salt from its saturated solution.

saturated solution is a solution containing maximum quantity of solute.

c) Distillation: a process to obtain a pure liquid from a solution of liquid mixture. - production of distilled water- petroleum fractions (fractional distillation)

Porcelin chips:To break up the air bubbles

Tap water flows to cool the vapour and condense it into liquid

To make sure the condenser is fully filled with water

is used to obtain pure liquid from a solution which contains impurities.

this method is used to separate two liquids (liquid mixture) that :

dissolve one another do not react possess different boiling points distillation involves the process of heating

liquid until it becomes vapour (gas) this vapour is then condenses to become pure

liquid.

distillation can be conduced to separate

mixtures of substances such as purifying alcohol from a mixture of alcohol and water and also purifying water from a mixture of water and salt.

the substance with a lower boiling point boils and vaporises earlier.

then the gas (vapour) will go through condensation to form the pure product of distillation.

Fractional distillation

distillation and crystallisation

are often used to obtain pure substances.

these purification methods have produced many substances for our daily needs.

Application of Purification

Method.

examples of the application of distillation : breaking crude petroleum into its fractions

such as petrol, kerosene and diesel to produce fuels and to make various kinds of plastic material.

production of pure water or distilled water for the preparation of chemical solution, medicine, as well as food and beverages.

obtaining pure ethanol from fermentation of sugar solution and yeast.

examples of the application of crystallisation :

production of salt from seawater. preparation of white sugar crystals from

sugarcane juice.