Physical change:
It is a change in the shape of the matter without any change in its structure.
Examples of physical changes:
1- Crushing of sugar.
2- Changing of water into ice or vapour.
3- Melting of wax.
Chemical change:
It is a change in the structure of matter producing another substance or substances of different properties.
Examples of chemical changes:
1- Burning of sugar.
2- Burning of paper.
3- Iron rust.
Q1: Give reasons:
1- Melting of wax is an example of physical changes.
Because the appearance is changed but the structure did not change.
2- Burning of sugar is an example of chemical changes.
Because the structure is changed giving a new substance with new properties.
3- Chemical change has a change in properties of matter.
Because it leads to the formation of new substances that have new properties.
Q2: What happens in the following cases?
1- Putting a piece of iron wire in water for several days, then exposing it to air.
" A layer of iron rust is formed.
2- Putting a cube of sugar in a burning spoon and heating it strongly.
" Sugar is burned and changed to another substance that has different properties.
It is a change in the shape of the matter without any change in its structure.
Examples of physical changes:
1- Crushing of sugar.
2- Changing of water into ice or vapour.
3- Melting of wax.
Chemical change:
It is a change in the structure of matter producing another substance or substances of different properties.
Examples of chemical changes:
1- Burning of sugar.
2- Burning of paper.
3- Iron rust.
Q1: Give reasons:
1- Melting of wax is an example of physical changes.
Because the appearance is changed but the structure did not change.
2- Burning of sugar is an example of chemical changes.
Because the structure is changed giving a new substance with new properties.
3- Chemical change has a change in properties of matter.
Because it leads to the formation of new substances that have new properties.
Q2: What happens in the following cases?
1- Putting a piece of iron wire in water for several days, then exposing it to air.
" A layer of iron rust is formed.
2- Putting a cube of sugar in a burning spoon and heating it strongly.
" Sugar is burned and changed to another substance that has different properties.
ليست هناك تعليقات:
إرسال تعليق