Light and Heat

LIGHT:

light travels in straight lines.

light also bends when it passes through a lens

Example of lens are :

Magnifying glass

microscope

spectacles

camera

telescope

dispersion of light through prism

White light is actually made up of different colours.

Dispersion of light through water droplets

HEAT :

Conduction

Heat can transfer from one part to another within objects

Convection:

the transfer of heat from one region to another by movement of fluids is know as convection.

Radiation:

radiation is the release of heat from surfaces of most bodies that is transferred directly from one region to another.

Chemical and Physical change

PHYSICAL CHANGE

When we mould , inflate , melt etc. its appearance may change but no new materials are formed.

These are some examples of physical changes:

inflating a balloon

cutting a cloth

melting a butter

moulding a clay

CHEMICAL CHANGE

chemical change is a change where new materials are formed

here are the examples :

burning a wood

mixing foods

cooking a food

MATERIAL AND PROPERTY

-Transparency of light

-insulator of heat

-conductor of heat

-conductivity of electricity

Choice of materials:

1. we choose steel because its strong
2. we choose rubber because its flexible
3. we choose wood because its stiff
4. we choose glass because it can help us see through

How to keep household items save , by putting them in the right

Here are the cautions :

Flammable

Corrosive

Poisonous

Toxic

BIOHAZARD

Explosive

Dangerous for the environment

so we must keep house hold items safely

• WEATHER

CLOUDS

• CUMULUS

Cumulus are clouds that look like cottons on the sky and is approximately 6,500ft(2,000m)

• Stratus

Stratus are clouds that are formed like horizontal layers and its below 6,000ft(2,000m)

• Cumulonimbus

Cumulonimbus are clouds that is vary big and tall and its altitude is 2,000m - 16,000m

• Cirrus

Cirrus are clouds that looks like stripes in the sky it is about 2,000m over .

• Nimbostratus

Nimbostratus are clouds that are dark and also forming layers and this cloud have an altitude that is 3,000m

FOG

Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface

DEW

Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening.

HAIL

Hail is a form of solid precipitation. It consists of balls or irregular lumps of ice