Monday, July 21, 2014

Inside the earth notes

L- 8    Inside the Earth
1.        Crust : The layer made up of solid rocks is called crust.

2.        Mantle: The thickest layer made up of molten or liquefied rock is called mantle.

3.        Core: The part of the earth made up of minerals like iron and nickel. There are two types of core
i)                  outer core –liquid in state
ii)                inner core – solid in state

Question and answers:
1.        What is the exterior of the earth made up of?
Ans The exterior of the earth is made up of mountains, plains, plateaus, valleys, desert etc.
2.        What is the interior of the earth made up of?
Ans. The interior of the earth is made up of three layers- Crust, mantle and core.

3.        Name the two types of the core.
Ans. The types of the core are – outer core and inner core.

4.        What is the difference between the outer and the inner core?
Inner core
Outer core
1.        It is in the solid state.
1.        It is in the liquid state.
2.        It consist of solid rocks
2.        It consist of liquefied rocks.

Fill up the blanks.
1.        The study of the interior of the earth is known as geology.
2.        The deepest drill into the earth is on the Kola peninsula in Arctic Russia.
3.        The interior of the earth increases with the depth.
4.        The molten state of rock is a thick liquid.
5.        The interior of the earth has excessive heat and high pressure.

Answer in brief:
1.        What are the causes of pollution?
Ans : The causes of pollution are
Ø cutting down trees
Ø  throwing waste in the rivers,
Ø smoke coming out of factories etc.

2.        How can we protect our environment?
Ans. We can protect our environment by
Ø growing more trees
Ø  not throwing factory waste in the water

Thursday, July 3, 2014

Matter and its Properties

Fill in the blanks:

1. Properties is to describe objects in many ways using their size, shape, colors, and textures.
2. Objects that take up space and have mass are called matter.
3. Matter is anything that is made up of atoms and molecules
4. An atom is the smallest particle of any substance/matter.
5. Two or more than two atoms together are called ‘molecules’.
6.  Solids have a definite shape, mass and volume.
7.  Liquids have a definite mass and a definite volume, but no definite shape.
8. Gases have a no definite shape, no definite mass and no definite volume.
9. Wood has a   fixed shape.
10.Liquid occupies space and has volume
11. A gas has no shape or size of its own.
12. On heating water changes to vapour.
13. Matter takes up space.
14. The shape of wood can be changed only by cutting or burning.


Name the following :
a.   Liquids  -- Milk, water ,juice etc
b.   Solids -- rice, roti , biscuits etc
c.   Gases—oxygen, carbon dioxide etc

Q.III Give reason:
1. Objects are heavy or light.
Ans : Because objects have different mass.
2. Ice changes to water when taken out of freezer.
Ans :   Because temperature changes.
3.The smell of burning incense stick spreads in the room
Ans : Because the molecules of the gas (smoke coming out of an incense stick)are   loosely held and thus able to move around freely.

What happens when?
Ø Water is boiled
Ans: It changes to water vapour.

Ø Mango milkshake is kept in the freezer
Ans : It will freeze and takes the shape of solid.

    Q.V Difference between the following:

Has fixed shape and size
Does not have fixed shape but has fixed volume.
Does not have fixed shape or volume
Molecules in solids are packed very tightly, so they do not move very easily.
Molecules in liquids are not packed very tightly, so liquids can flow.
Molecules of gases are spread out in an open space freely.
Size of a solid does not change unless it is heated, cooled, broken or cut.
e.g. book, table, glass
Liquids take the shape of the container in which they are held.
e.g. water, juice, milk etc.
Gases cannot keep their shape and most gases are colourless.
e.g. Oxygen, Carbon dioxide etc.

Q-VI Draw the three forms in which water exists.

Q-VII Draw arrangements of molecules.