STRUCTURE AND PROPERTIES OF MATTER

Structure of Matter

State of matter is defined in terms of the phase tr ansitions which indicate the change in structure

and properties. Solids, liquids and gases all are made up of microscopic particles. The behavior

of all these particles also varies in three phases.

The Concept of Matter

Explain the concept of matter

Matter

is anything, such as a solid, liquid or gas, that has

weight

(mass) and occupies space. For

anything to occupy space, it must have

volume

.

The Particular Nature of Matter

Justify the particulate nature of matter

Matter is made up of tiny particles. The particles are atom or molecules, examples of substances,

which  are  made  up  of  atoms,  are:  gold,  copper,  Argon  and  silver;  and  those  made  up  of

molecules includes oxygen, water and ammonia.

In  solid,  storm s  attractive  forces  hold  molecules  together  so  that  they  are  not  free  to

move but they can only vibrate about their mean positions.

In liquids there are weak forces of attraction between molecules ther efore the molecules

are free to move randomly. The distances between molecules in liquids ar e therefore are larger

than in solids.

In case of gases the molecules experience ver y weak forces of attraction and hence they are free

to  move  randomly  filling  the  whole  space  of  the  containing  vessel.  The  distances  between

molecules in  gases  are  comparatively  greater  than those  in  solids  and liquids  as shown in  the

figure above.

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Demonstration to show the intermolecular space in solids, liquid and gases.

The Kinetic Theory of Matter

Explain the kinetic theory of matter

Generally, when solid particles are placed in the source of lead the particles tends to move from

hot area to cold areas. These particles move because it gains ener gy that called it Kinetic energy.

Kinetic  theory  of matter  sometimes  attempts  to  explain  how  properties of  gases like  pressure,

temperature and volume remain in constant motion.

There are three main parts of the Kinetic theory of matter. This includes:

1.

Matter is made up of tiny invisible part.

2.

Matter comes in different sizes.

3.

There is a point that the smallest particles of matter can be the fastest.

Therefore  kinetic  theory  of  matter  states,  “All  matter  is  composed  of  small  particles”Or

“Particles  of matter  are  in  steady  motion  and  that  all  impacts  between the units  of  matter are

completely elastic”

Three States of Matter

Classify three states of matter

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There are three states of matter, namely:

1.

Solid state

2.

Liquid state

3.

Gaseous state

Solid state is the state of matter, which include solid materials, in which the intermolecular force

between molecules are greatest and distance between molecules is small. Examples of solid state

are wood, iron, etc.

Liquid sate is the one of the state of matter in which the intermolecular forces are low compared

to solid state, there is greater distance between one molecule and another. See on figure 1.0 (b)

examples water, soda, kerosene, and petroleum.

Gaseous state is the state of matter in which there is no intermolecular forces between molecules

hence molecules are fr ee  to move from one  place  to another  examples  of gases are hydrogen,

oxygen, carbon dioxide gas.

Difference between solid state, liquid state and gaseous state of matter

Solid state

Liquid state

Gaseous state.

It concerns with solid matter  It concerns with liquids/ fluids matter  It concerns with gases

Have high intermolecular  Low intermolecular force  No intermolecular force

No distance between molecules  There is little distance between molecules  Molecules are far from each other

Good  examples  are  iron  materials,

Good  examples  are  water,  soda,  kerosene

Good  examples  are  oxygen  and

woods etc.

and petrol

hydrogen

Rownian Movement

According  to  Robert  Brown:

Brownian  movement  refers  to  the  irregular  motion  of  tiny

particles suspended in fluid (liquid organs). Consider the demonstrationbelow

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Robert  Brown,  an  English  Botanist,  powered  some  pollen  grain  in  water  and  observed  that

particles floating in the water were darting about.

The  irregular  motion  of  tiny  particles  suspended  in  a  fluid  (fluid  or  gas)  is  called  Brownian

movement.

The tiny particles dart about because liquid molecules that are in state of motion bombard them.

Elasticity

The Concept of Elasticity

Explain the concept of elasticity

When a force is applied to a body the dimension of the body is usually altered. If an iron wire is

stretched by small force applied to it longitudinally, the wire returns to its original shape and size

when the force is removed.

Elasticity can be defined as the property of the iron wire by which it recovers its original shape

and size on removal of the stretching force.

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The  Relationship  between  Tension  and  Extension  of  a  Loaded  Elastic

Material

Justify the relationship between tension and extension of a loaded elastic material

Consider the graph below:

Point A is called the elastic limit. The straight region OA of the graph has a slope K given by the

ratio.

K= Tension/Extension

The ratio is called the force constant or coefficient of stiffness of the wir e and it is expressed in

newton per metre (N/M)

The Application of Elasticity in Real Life

Identify the applications of elasticity in real life

In  everyday life  we  often  actually do  the activities that  are concerned with the  application  of

physics. Here are some of the application of physics in ever yday life especially in the application

of Elasticity:

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Spring mattress. When you sit or sleep on a spring mattress, futon style push your weight.

Pressured by the compressed spring mattress. Due to the nature of its elasticity, stretch a spring

mattress again. Spring will be stretched and compressed, and so on.

Spring that  is  used as  shock absorbers  on motorcycles. Springs  used in  the suspension

systems of motor vehicles. The purpose of this is to dampen spring a surprise when a motorcycle

driven through an uneven road surface.

Another simple example and that you may often come across is the catapult. When it was

about to shoot birds with catapults for example, rubber slingshots first stretch (given the gravity).

Due to the nature of its elasticity, long rubber  slingshots will return to normal after a tensile force

is removed.

Adhesion and Cohesion

The Concept of Adhesion and Cohesion

Explain the concept adhesion and cohesion

Matter is made up of molecules. That exerts force of attraction. This force of attraction may be

either Cohesion or Adhesion.

Cohesion is the force of attraction between the molecules of the same substance, example

water to water molecules.

Adhesion is the force of attraction between the molecule of different substances example

water to glass molecules.

Water  molecules  can  experience  the  force  of

cohesion

among  themselves,  where  water

molecules and glass molecules will experience force of

adhesion.

Definite shapes of a solid are due to strong cohesion force among its molecules.

Shapes and meniscus of a liquid

When we carried out activities involving determination of volume in a liquid ring and measuring

cylinder. The description indicated that the surface of  the liquid was carved, forming a meniscus,

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and that the volume must be read at the bottom or top of the meniscus, depending on the liquid

used. For mercury, the top of the meniscus is read.

The formation of a meniscus in a liquid is due to forces of adhesion between the liquid and the

walls of the container. The adhesion of the liquid such as water to the wall of a vessel causes an

upward force on the liquid at the edge.

The opposite takes place in mercury, the meniscus of water curves upwards forming a concave

shape. When a drop of each liquid, mercury and water are placed on a glass sheet, water spreads

further unlike mercury, because of mercury s high cohesion force among its particle.

Why water wets the glass?

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Why methanol does not wet the glass?

Applications of Adhesion and Cohesion in Daily Life

Identify the applications of adhesion and cohesion in daily life

Application include the following

1.

To stick two different objects together. Here we use the adhesive effects of tape or glue.

2.

Adhesion can also  be used  to remove harmful  materials such as bacteria  from drinking

water. Adhesive forces are the source attraction substance.

3.

Cohesion assists in transport of water in plants and animals by allowing one molecule to

pull others along with it.

4.

The bodies of plants and animals also use the cohesion of tissue to repair damage.

5.

Ink sticks on paper because of adhesive force between the paper and ink.

Surface Tension

The Concept of Surface Tension

Explain the concept of surface tension

While  you  may not be able  to walk  on water, water stride does. This is due  to the property  of

liquid, which is known as surface tension.

Surface  tension  is the ability of the molecules on the surface of a liquid to  attract and  stick to

each  other  allowing  them  to  resist  an  external  force.  Surface  tension  enables  insects  such  as

water strides and mosquitoes to walk on water. It allows small objects even metallic ones such as

needles and razor blades to float on the surface of water.

Surface  tension  is  a  resultant  attractive  force  between  molecules  in  a  liquid.  The  molecules

below  the  surface  liquid  have  forces  of   attraction  between  neighbouring  particles.  However

molecules at the  surface  have no  neighbouring molecules above  them. This makes them  have

stronger attractive force than their nearest neighbours on the surface.

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However, when some  detergent is  added  to  water, the same  objects sink  to  the bottom  of the

trough. This means that the detergent interfered with the surface of the liquid so decreasing the

tension of the water surface.

Detergents  are  example  of  surfactants.  A  surfactant  is  a  substance  that  reduces  the  surface

tension of a liquid.

Note:

the term surfactant is an aerogun for surf ace-active agent.

Surface tension is affected by the f ollowing

Nature of the liquid

Contamination/impurities

Temperature

Application at surface tension:

1.

In extraction of impurities dating laboratory process.

2.

Surfactants are also used to make emulsion of liquid like oil and water.

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3.

In cleaning action of soap.

Applications of Surface Tension in Daily Life

Identify the applications of surface tension in daily life

Application at surface tension

1.

In extraction of impurities dating laboratory process

2.

Surfactants are also used to make emulsion of liquid like oil and water.

3.

In cleaning action of soap

Capillarity

The Concept of Capillarity

Explain the concept of capillarity

This is the tendency of a liquid to rise in narrow tubes or to be drawn into small openings such as

those  between  the fibres  of a towel.  Capillarity  can pull  a  column  of  liquid upward  until  the

weight of liquid becomes greater than the surface tension.

In  a  tube,  capillarity depends  on  the tube s  diameter  but  weight  of water  column depends on

other factors besides it.

The smaller the radius of the tube the higher the liquid will rise in it. This implies that capillarity

height is immensely proportional to the diameter of the tube.

By definition

Capillarity is defined as the tendency of liquid to rise in narrow tubes or to be drawn into small

openings such as those between the fibres of a towel.

Capillarity action is the ability of a liquid to raise or fall in a narrow tube.

Note:

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1.

Capillarity depends on the type of liquid. For example if you dip capillarity tube in water

the water rises in the tube and above the level of the water in the vessel.

2.

If the tube is dipped in mercury, the liquid does not rise in the tube. It suffers capillarity

depression.

Applications of Capillarity in Daily Life

Identify the applications of capillarity in daily life

The application includes:

1.

Capillarity is essential to plants and animals.

2.

In plants,  it  facilitates  the transport of  water  and  nutrients f rom the  roots  to  the leaves

where photosynthesis produces the plants food. In animals it assists in the circulation of blood.

3.

Capillarity promotes the movement of ground water.

4.

It is the principles on which paper and f abric towels work to absorb water.

5.

Cotton clothing in hot climates uses capillarity action to draw perspiration away from the

body.

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6.

In an oil or kerosene lamp capillarity draws the fuel  up into the wicker where it can be

burnt.

7.

A writing Rubin splits in the middle so that a fine capillary is formed.

Osmosis

The Concept of Osmosis

Explain the concept of osmosis

Defined  as  the  movement  of  a  solvent  from  a  region  of  low  concentration  through  semi

permeable membrane.

Particles will diffuse through the membrane in an attempt to equalize the concentration on either

side. E.g. two solutions of different concentration separated by a semi permeable membrane. The

membrane is permeable to the smaller solvent molecules but not to the larger solute molecules.

Osmosis stops when the concentration becomes the same on either side of the membrane.

Osmosis stops when the concentration becomes the same on either side of the membrane.

Applications of Osmosis in Daily Life

Identify the applications of osmosis in daily life

Applications of osmosis in daily life:

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1.

Control the movement of water and nutrients in and out of the cell.

2.

Filtration processes.

3.

Removal of harmful ingredients from drinking water.

4.

Removing salt from seawater so as to make it suitable for drinking and for other domestic

uses.

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