Question

please help me class 6th subject science NCERT lesson changes around us​

Answer 1

Answer:

idk

Explanation:

Answer 2

Answer:

1

(a) irreversible

(b) reversible

(c) irreversible

(d) reversible

(e) irreversible

2

(a) natural

(b) natural

(c) natural

(d) man made

(e) natural

3

(a) Burning of candle wick is irreversible change because when we burn candle wick we cannot get it back. Burning of candle wax is a reversible change because we can reshape wax and melt it again.

(b) Burning of an incense stick is a irreversible change because when we burn incense stick a new substance ash and smoke is formed. Now we cannot get back the incense stick. So it is a irreversible change.

(c) While fixing a metal rim on a wooden wheel. Normally, the size of the metal rim is slightly smaller than that of the wooden wheel. While fixing the metal rim, it is heated. It becomes slightly larger in size and now it can be fixed onto the wooden wheel. On cooling, it contracts and fits tightly onto the wheel.

(d) Freezing of water to ice is an physical change because it is reversible change, we can brought ice back to water. Most of physical changes are reversible.