Advertisements
Advertisements
Question
When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.
Advertisements
Solution
- When a candle burns, the melting of wax is a physical change and the burning of the candle is a chemical change. When the wax melts, only its physical properties change.
- Hence, it is a physical change. When a candle burns, its chemical properties and composition change, the melted wax turns into carbon dioxide and other substances and it cannot be obtained in its original form.
- It is a chemical change. Hence, when a candle burns, both physical and chemical changes take place.
Example:
When coal is broken into pieces and burned, both physical and chemical changes occur. Breaking coal into pieces is a physical change. The properties of coal do not change in this. Burning of coal is a chemical change. Due to burning, the chemical properties of coal change and new substances are formed.
APPEARS IN
RELATED QUESTIONS
Fill in the blank
change in which the substance can be brought back to its original state is called a ............... change.
State three differences between evaporation and boiling
Write true or false
Rusting of iron is a chemical change.
Classify the following as physical or chemical change :
Formation of curd from milk
Classify the following as a physical or a chemical change.
Boiling of water
Classify the Following as a Physical Or a Chemical Change.
Curdling of Milk
Distinguish between the following.
Physical change and chemical change
What will you take into account while identifying the following?
A physical change in a substance.
State what is meant by the term – interconversion of matter. Is interconversion of matter a physical change or a chemical change.
Give two examples for the following case:
Physical changes which are not reversible
