Define a chemical change and list its
characteristics. Give three examples of
chemical changes.
Answers
Answer:
a chemical change is a permanent change in which the chemical composition of a substance is changed and one or more new substances with different chemical composition and different properties are formed.
it is not easily reversible. it always involves chemical reaction
Nacl + Agno3- Agcl+ NaNo3
CuCo3- CuO+ CO2
H2+Cl2-2HCl
chemical change in detail
1) The change which affect the both physical and chemical properties (composition of substances) is called chemical change.
2)new substances are formed in chemical change
3)A chemical change can either be reversible or irreversible but the most of the chemical changes are irreversible
4)The molecules of the substance changes to form new molecules thus, the product is chemically different from the substance
5) The amount of energy required to carry out a chemical change is small.
examples of chemical change
1) burning of charcoal
2) baking of cake
3) photosynthesis
4) burning of matchstick
characteristics of chemical change
- chemical change is the result of a chemical reaction between reactants to form one or more products
- new substances with different properties are formed
- chemical changes are mostly irreversible in nature
- the amount of energy involved in a chemical change is substantial as in the case of burning.