class 7 chapter 6 science
please give me answer and you too make brainlist
Answers
1 and 3 are physical changes.
2 and 4 are chemical changes
this is the answer for ur 1st question
2.It has no change
3.Conversion of ice into water and water into ice is an example of change which can be reversed.
4.white flame
5.evaporation
6.When carbon dioxide is passed through lime water then the lime water turns milky due to the formation of calcium bicarbonate.
Chemical reaction takes place as:
CO2+Ca(OH)2→CaCO3+H2O
7.Physical change
Chemical change
1. No new substances with new properties are formed.
1. New substance with new properties are formed.
2. It can be reversed by simple physical methods.
2. Change cannot be reversed by simple physical methods.
3. It is temporary change.
3. It is permanent change.
4. Energy is neither needed nor produced.
4. Energy is either needed or evolved
8.The essential component for rusting is the contact of metal with oxygen and moisture. When the iron gate is painted, it protects the iron to get in contact with oxygen, hence prevents it from rusting