1. Differentiate between a) Chemical and physical changes b) Fast and slow changes c) Desirable and undesirable changes
Answers
Explanation:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. ... All chemical reactions are reversible although this can be difficult in practice.
Answer:
a) Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes: Chemical changes cause a substance to change into an entirely substance with a new chemical formula.
b)The changes that take a long duration of time to complete, are called slow changes. This duration can be in hours, days or even months. The changes that are completed in short or very short duration of time are called fast changes.
c)Desirable Changes: Those changes which are desired to occur that is, we want them to take place are known as desirable changes. Examples: ripening of fruits, germination of seeds etc. Undesirable change: Those changes which we do not want to take place are called undesirable changes
Explanation: