properties of matter frx

Physics

Form two

Chapter one

Properties of matter

Prepared: Farah khadaad

Properties of Matter

Particular nature of matter

Look around the classroom everything, from the clothes you are wearing to air you breath is matter , matter is very important matter makes up everything including living things like plants and people , it also makes non-living things such as tables and chairs

Things as big as an elephant or as tiny as a grain of sand on a beach are matter

Matter: is everything that it takes up space and has mass

Everything is matter and matter comes in three different states

Solid Liquid And gas

That means that everything is either a solid, a liquid or a gas Each state has properties

Properties of solids

Solid don’t change shape easily Thing of a piece of paper you can change its shape by crumpling it, but it does not change its shape by itself, you have to use your energy to make the shape change. If you put a solid in a container it would not change its shape

Solid particles do not move around Solid particles are in an aligned array look at the pictures (notice) the

particles are lined up in tight row, they can’t move.

Property of solid Why they are like this

Farah yasin (khadaad) physics/ properties of matter

They have a fixed shape and cannot flow

The particles cannot move from place to place

They cannot be compressed or squashed

The particles are close together and have no space to move into

Properties of liquids

Liquids take the shape of their container, if you pour milk into a glass it will take the shape of the glass, if you pour the milk into a bowl it takes the shape of the bowl.

Liquids have surface tension, the particles hold on to each other, like holding hands with a friend, the surface of a glass filled with water holds together because the particles hold one to each other that is called surface tension.

Liquids move around; the particles in liquids are farther apart than these of solids so they can move around more, that’s why liquids take the shape of their container.

Properties of liquids Why they are like this They flow and take the shape of their container

The particles can move around each other

They cannot compressed or squashed The particles are close together and have no space to move into

Properties of gases

Gas is invisible that means you can’t see it, the particles are so far apart they are invisible, but they are still there! Thing about oxygen, you can’t see it, but you know it’s there because you breath it

Gas particles move around freely; they are spread out move fast, like when you are running on the playground at recess.

Properties of gas Why they are like this

They flow and completely fill their container

The particles can move quickly in all direction

They can be compressed or squashed The particles are far apart and have space to move into


Challenge questions

1. What is the matter? 2. State two different between solids and gases 3. Think about a can of soda all three states of matter are there

a. What part is solid matter?b. What part is liquid matter?c. What part is gas matter

4. What about you? All three states of matter are a part of you a. Name a part of you that is solid?b. Name a part of you that is liquid? c. Name a part of you that is gas?

5. A basketball has only two states of matter, what two states of matter are in a basketball?

6. Which Statement is True?A. Liquids have a definite shape and volumeB. States of matter are defined by the substances they are made up ofC. Gases have a definite shape and volumeD. Solids have a definite shape and volume

7. Draw a diagram of A. Gas particlesB. Liquid particlesC. Solid particles

Kinetic theory of matter

The kinetic particle theory explains the properties of the different states of matter. The particles in solids, liquids and gases have different amounts of energy. They are arranged differently and move in different ways this is called” kinetic theory of matter”


This table summarizes the arrangement and movement of the particles in solids, liquids and gases, and shows simple diagrams of the arrangement of the particles that you should be able to recognize.

Summery

Solid Liquids gasArrangement of particles Close

together regular pattern

Close together random

Far part

Movement of particles Vibrate about a fixed position

Move around each other

Move quickly an any direction

Diagram

The particles in solids, liquids and gases have different amount of energy, in gases the particles have most energy and are moving around at high speed, particles in solids are fixed and can only vibrates they have less energy than the particles in liquids which are free to move.

As the temperature increases the size of the vibrations or the speed of the particles increases the particles are taken up more space and substance expands

When the temperature decreases the particles have less energy, in a solid they vibrate less and so take up less space the solid contract.

In liquids and gases the particles also have less energy, and move more slowly the gas or liquid becomes denser as the temperature decrease.

Phase Change

As you know, if you heat a block of ice, it won’t simply get warmer. It will also melt and become liquid. If you heat it even further, it will boil and become a gas. When a substance changes between being a solid, liquid, or gas, we say it has undergone a phase change.


Melting

When a solid is heated, the particles are given more energy and start to vibrate faster. At a certain temperature, the particles vibrate so much that their ordered structure breaks down. At this point the solid melts into liquid. The temperature at which this change from solid to liquid happens is called the melting point. Each solid has a set melting point at normal air pressure. At lower air pressure, such as up a mountain, the melting point lowers

• Melting point - SPECIFIC temperature when melting occurs

• Each pure substance has a SPECIFIC melting point.

Substance Melting point °CWater 0°CNitrogen -210°CSodium 98°CCommon salt 801°CSilver 962°CCarbon 3500 °C

Freezing

Lava is liquid rock, which erupts through a volcano at temperatures as high as 1,500ºC (2,732ºF) through a volcano. However, the red-hot lava cools as it meets the Earth’s surface, and turns back into solid rock again. This change from liquid to solid is called freezing or solidifying. It is the opposite process to melting.

Boiling

When a liquid is heated, the particles are given more energy. They start to move faster and further apart. At a certain temperature, the particles break free of one another and the liquid turns to gas. This is the boiling point. The boiling point of a substance is always the same; it does not vary


• Boiling Point: is temperature at which a liquid boils

• Each pure substance has a SPECIFIC boiling point

Substance Boiling point oCWater 100°CNitrogen -196°CSodium 883 °CCommon salt 1413°CSilver 2162 °C Carbon 4027 °C

Invisible steam

Water boils when it reaches its boiling point of 100ºC (212ºF). This is the temperature at which water turns to steam. Steam is an invisible gas. When it reaches the lid it cools back to a liquid.

Evaporations

Even without boiling water in a kettle, some of the liquid water changes to gas. This is evaporation. It occurs when a liquid turns into a gas far below its boiling point. There are always some particles in a liquid that have enough energy to break free from the rest to become a gas.

Condensation

Dewdrops are often found on a spider’s web early in the morning after a cold night. Water that is present as a gas in the air cools down and changes into tiny drops of liquid water on leaves and windows. This change from gas to liquid is called condensation.

Exercises

1. Define, in your notes, each of the following:a) Meltb) Freezec) Evaporated) Condense

Part two: multiple choice questions


1. Ice cubes in a warm drink willa. Meltb. freezec. not change

2. The liquid drink _________ energy.a. loses b. gains c. does not change

3. The ice ___________energy.a. loses b. gains c. does not change

4. The final temperature of the ice and liquid is a. the same b. different

5. Which one of the following statement is not true?a. the molecules in a solid vibrate about fixed position b. the molecules in a liquid are arranged in a regular pattern c. The molecules in a gas exert negligibly small forces on each other except during

collisions.d. The densities of the most liquids are about 1000 times greater than those of gas

because liquid molecules are much closer together than gas molecules.e. The molecules of a gas occupy all the space available.

Diffusion

If someone is cooking in the kitchen it doesn't take long for the smell to travel around the house to other rooms. This is because of diffusion.

Diffusion in gases

When chemicals, like the smell of perfume or burning toast, are let loose in a room, the particles mix with the air particles. The particles of smelly gas are free to move quickly in all directions. They eventually spread through the whole room. This is called diffusion.


You don't have to mix the gases by waving your arms around - it mixes on its own. Diffusion in gases is quick because the particles in a gas move quickly. It happens even faster in hot gases

Diffusion in liquids

Diffusion can also happen in liquids. This is because the particles in liquids can move around each other, which means that eventually they are evenly mixed.

For example if you drop a little bit of paint into a jar of water the colour will spread slowly through the water. This is by diffusion.

Diffusion in liquids is slower than diffusion in gases because the particles in a liquid move more slowly.

Solids

Diffusion does not happen at all in solids because the particles in a solid can only vibrate on the spot, rather than being able to move from place to place.

Brownian motion

In 1827ropert brown discover that very tiny pollen grains suspended in water are continually moving they make small, irregular movements in random directions, the particles in smoke can be seen to do the same thing

The effect is thought to be due uneven bombardment of the pollen or smoke particles by the liquid or gas particles which surrounding them.

Very small particles are needed for the movement to be seen if the particles are large then there will be equal numbers of collisions from every side and the effects will be cancel out but a small particle is more likely to be unevenly bombarded, so it moves until struck again, the effect can be seen in a smock cell it is called Brownian motion


The kinetic theory explains Brownian motion as follows, the bits of smoke are just big enough to be seen but have so little mass that they are jostled about thousands of particles in the surrounding air bump in to them at random.

Properties of materials

Surface tension

• The interior molecules are equally attracted by all neighboring molecules with the same force, so that the resulting force is zero.

• The molecules at the surface are attracted by molecules from inside, whereas no force from outside the surface. Hence the resulting force is towards the interior of the liquid.

Surface tension: is defined as the force along a line of unit length, where the force is parallel to the surface but perpendicular to the line


Cohesion and Adhesion

Forces of attraction between a liquid and a solid surface are called adhesive forces. The difference in strength between cohesive forces and adhesive forces determine the behavior of a liquid in contact with a solid surface.

Water does not wet waxed surfaces because the cohesive forces within the drops are stronger than the adhesive forces between the drops and the wax.

Water wets glass and spreads out on it because the adhesive forces between the liquid and the glass are stronger than the cohesive forces within the water.

When liquid water is confined in a tube, its surface (meniscus) has a concave shape because water wets the surface and creeps up the side.


https://en.wikipedia.org/wiki/File:Surface_Tension_Diagram.svg

Mercury does not wet glass - the cohesive forces within the drops are stronger than the adhesive forces between the drops and glass. When liquid mercury is confined in a tube, its surface (meniscus) has a convex shape because the cohesive forces in liquid mercury tend to draw it into a drop.

Capillary action

Capillary action (sometimes capillarity or capillary motion) is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper

Summery

SURFACE TENSION: is defined as the force along a line of unit length, where the force is parallel to the surface but perpendicular to the line.

INTERMOLECULAR INTERACTIONS

ADHESION force between two different bodies (or different surface layers of the same body).

COHESION force attraction between like-molecules.

CAPILLARITY: is the ability of a liquid to flow in narrow spaces without the assistance of external force.

Before you choosing a material, a designer must know how it behaves under various type of force.Important properties are


http://en.wikipedia.org/wiki/Liquid

http://en.wikipedia.org/wiki/Gravitation

http://en.wikipedia.org/wiki/Liquid

http://en.wikipedia.org/wiki/File:Capillarity.svg

Strength : is the ability of material to resist beaking when stretched, compressed or sheared

Ductility: is the ability of a material to deform when a force is applied, plasticince is very ductile, copper is ductile stainless steel is less ductile.

Elasticity: is the ability of a material regains its original shape after being deformed, spring steel is elastic so is rubber.

Brittleness: is the brittle materials break readily when their elastic limit is reached. They do not show any noticeable extension when they are stretched they snap suddenly, blackboard chalk, glass and dry twigs.

Stiffness: is the resistance which the material offers to forces which tend to change its shape or size, this can be effected by the shape of the article, a sheet of paper is stiff in the plane of the paper but not stiff at right angles to it.

Questions

1. Define the following terms a. Diffusion b. Brownian motion

c. Surface tension

d. Cohesion

e. Capillarity

f. Stiffness

g. Ductility

2. Explain why? a. Diffusion occurs more quickly in a gas than in a liquid b. Diffusion is still quite slow even in a gas c. An inflated balloon gradually goes down even when tied

3. Ahmed uses microscope to look at smoke particles he sees the smoke particles moving randomly .what makes the smoke particles move randomly?

4. Why diffusion does not happen at all in solids?5. Why diffusion in liquids is slower than diffusion in gases?

EndFarah yasin (khadaad) physics/ properties of matter Prepared farah khatat

properties of matter frx

Education

shape solid particles

solid matter

orsquashedthe particles

liquid matter

different states of

important matter

breathis matter

shape change