(1)

Give Reason 

 

                   A mixture of sand and iron filings can be separted easily 

 

Because it can be separated by magnet


(2)

The magnet attracts iron, but it does not attract copper

Because iron is magnetic substance while copper non-magnetic


(3)

The chalk appears white, while the board appears black

Because white reflect all colors while black absorb all colors


(4)

 The rainbow appears in the sky after heavy rainfall

Due to the refraction of light in water drops of rain


(5)

Chameleon simulate the color of the surrounding environment

To hide from enemies


(6)

Seeing the spoon bending = broken in a cup of water 

Due to light refraction


(7)

Some bees look like wasps in forming lines on their bodies

To fare their enemies


(8)

:What happen 

Heating salty solution gently

 

Water evaporate, and salt remain


(9)

Adding an amount of sugar to water with stirring

Sugar will dissolve in water


(10)

Dissolving an amount of salt in hot water

A homogenous mixture is formed


(11)

- Passing white light through a glass prism

It will be split into seven colors