Lesson 1 Science

Grade 7

Matter and its
charachteristics

The Curriculum

Initial

Advanced

Matter

Atomic
structure

Energy

Energy

resources

Diversity

Adaptation

1) BLB instructions
2) Introduction for the curriculum
3) Classroom Discipline and rules
4) Physical properties of the matter

Objectives

What is matter ????

● Everything around us on earth’s surface is

called matter

● Def: it’s anything that has mass and volume

Mass

Mass: it’s the amount of matter that the body contain

Measuring unit: gm or Kg

Volume

It’s the space that is occupied by the body

Measuring unit: cm³, m³ or L

01

1- what do you know about physical

properties

2- what do u want to know ?

3-what do learned ?

KWL

Density

01

1-Physical properties

Boiling point

02

Electric

conduction

04

Hardness

03

05 06

Melting point

Color and

taste ,
smell
07

Heat

conduction

We can differentiate between

Iron , Silver and Gold

We can differentiate between

Sugar , table salt and
Flour

We can differentiate between

Vinegar and perfume

01 Color and taste , smell

We can differentiate between , Silver

and Gold by …………

We can differentiate between
Sugar , table salt and Flour by

…………..

We can differentiate between

vinegar, perfume by …………..

Quick Check

How can u defferntiate between

the three below

A

C

B

02 Density

What do you think

What's meant by Density ????

FOCOUS and WATCH THIS

VIDEO

https://www.youtube.com/watch?v=GnBQ6

vIutDM&t=55s

Home

Open in new tab

Copy link

So from the video

1-Matter is any thing that has ……..And
………….

2- All substances have the same density ?

3- Density is ………… per unit Volume

02 Heads together

Density

Def: it’s the mass of unit volume of a substance

OR

it’s the mass of one cubic cm of a substance

Density = 𝑀𝑎𝑠𝑠 𝑖𝑛 𝑔𝑚 ÷ 𝑣𝑜𝑙𝑢𝑚𝑒 𝑖𝑛 𝑐𝑚3

Measuring unit is gm/cm³

N.B: the density of a matter is a fixed value,

whatever the used volume or masses differ

●
Each substance has its own density There are not two substances that

have the same density.

●
G.R. 1- Equal volumes of different substances have different masses.

●
2- Equal volumes of different substances have different volumes.

●
Due to the difference in density.

Quick Check

● IF you have Mass , Density and Volume

● How can you make a magic triangle that obeys the

density law ????

M

V

D

Any Question ???

●
Q: what is meant by

1. the density of water is 1 gm/cm³ ?
2. The mass of 3 cm3 of a matter is 9 gm?
3. The density of a matter is 7.8 gm/cm3 ?

●
Q: G.R.F

1. Equal masses of different substances have different volumes

2. Equal volumes of different substances have different masses

1- What is the density of the oil, if 80 gm of oil occupies 100 cm3 ?

2- Calculate the mass of 1000 cm3 of milk knowing that its density
is 1.03 gm/cm3.

3- Calculate the volume of 500 gm of iron if its density is 7.8
gm/cm3.

4- A piece of iron is put in a beaker contains 100 cm3 of water the
volume becomes 150 cm3 if the mass of this piece is 390 gm,
calculate the density if the iron.

5-A piece of wood is put into a beaker of water its mass was 200
gm, if the mass become 270 gm and the volume of this piece is 100
cm3, calculate the density of the wood.

Floating and sinking

●
Matter that has density more than that of water sinks in
water. (SM)

●
Matter that has density less than that of water floats on
water. (FL)

●

●
Matter that has density larger
than that of water sinks in water.

● Life applications of density

1-Balloons filled with helium or hydrogen rise up in the air carrying
flags during festivals???
Because the densities of helium and hydrogen are less than the
density of air.
2- Water is not used to put out (extinguish) petrol fires
Because the density of petrol is less than that of water so, petrol
floats on water surface and water doesn’t put out the petrol fires.

3- The change in the density of matter is used to check the purity of
matter {As determination of the quality of milk}.

Give reason for

1-A piece of cork floats on the surface of water, while a coin
sinks in water.

The density of cork is less than water so it floats on its surface,
While the coin is more dense than water so it sinks in it.

2- Balloons filled with hydrogen and helium rise up.
the density of petrol is less than that of water so, petrol floats
on water surface and water doesn’t put out the petrol fires.

03 Melting point

● It is the temperature at which matter begins to change from a

solid state to a liquid state( begins to melt )

Melting: Is the change of matter from
solid state to liquid state by heating.

●
What is meant by? The melting point of ice = 0°C.

● This means that ice begins to change into water at 0°C.

●




Each substance has a definite melting point which is used
to differentiate among different substances.

Substances can be classified according to melting points into:

●
Substances have low melting points: Ice, wax & butter.

●

●

●
Substances have high melting points: Iron, copper, aluminum.

● Life Applications of Melting Point:

1.Workmen melt the solid metals. G.R.
To be easy for mixing and shaping to form alloys

●
as:

1-Copper-gold alloy that is used in making jewels.

2- Nickel-chrome alloy that is used in making heating coils.

2. Cooking pans (pots) are made up of aluminum or stainless
steel alloy which does not rust. G.R.

Due to its high melting point.

● It is the temperature at which matter begins to change from a

liquid state to a gaseous state

Boiling : It is the change of matter from liquid state to gaseous state by
heating.

04 Boiling point

● What is meant by? The boiling point of water = 100°C. T

● This means that water begins to change into water vapor at

100°C

● Each substance has a definite boiling point which is used to

differentiate between different substances

● Life Applications of Melting Point: The separation of the

components of crude petroleum oil by heating. G.R.

● Due difference between them in boiling point.

Solid substances are divided according to hardness into:

05 Hardness

●
Life applications of hardness

● 1. The screwdrivers are made up of steel iron. G.R.

● Because iron is very hard.

● 2. The rods used in building concrete houses are made up of

iron not copper. G.R.

● Because the hardness of iron is more than that of copper

06 Electric conduction

● Life Applications of electric conduction:

●
1-Electric wires (or cables) are made up of copper or aluminum and
covered with a plastic layer. G.R.

●
Because both of copper and aluminum are good conductors of electricity,
while plastic is a bad conductor of electricity.

●
2-Electric screwdrivers are made up of steel iron, while their handles are
made up of wood or plastic. G.R.

●
Because steel iron is a good conductor of electricity, but wood and plastic
are bad conductors of electricity.

07 Thermal conduction

● Life Applications of Thermal Conduction:

1-Cooking pans are made up of aluminum. G.R.
Because aluminum is a good conductor of heat and it has a high melting
point.

2 -Handles of cooking pans are made up of wood or plastic. G.R.
Because wood and plastic are bad conductors of heat.

2-CHEMICAL PROPERTIES

● Metals and chemical activity:

●
Very active metals: Metals which react with oxygen when they are
exposed to humid air, so they lose their metallic luster.

●
Examples: Sodium and potassium.

●
Life Application of chemical activity:

●
Sodium and potassium are kept under kerosene surface. G.R.

●
To prevent their reaction with atmospheric oxygen.

●
Less active metals: Metals which react with oxygen if they are left

●
in air for some days forming a layer of rust.

Examples: Iron, aluminum and copper.

Life Applications of chemical activity:
1-Steel bridges and the holders of light bulbs are painted from time to time.
G.R.
To protect them from rust and corrosion.
2-Aluminum cooking pans are washed with a rough material. G.R.
To remove the rust layer formed on their surfaces.
3-Metallic spare parts of cars are covered with grease. G.R.
To protect them from rust and corrosion.

●
Inactive metals: Metals which find great difficulty in reacting with oxygen.
Examples: Silver, gold, nickel, platinum and chromium.

Life Applications of chemical activity:
1-Gold, silver and platinum are used in making jewels. G.R.
Because they are chemically poor active.

2-Nickel, gold and silver are used to cover other substances which rapidly
gain rust such as iron. G.R.
To protect them from rust and corrosion.

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