Unit 11 energy

04.19.2020
08:12:42
Dear students, good morning
Today's topic : evaporation
Pg.no : 172 & 173 in Ur cambridge check point science grade 9
The important points are
1.Evaporation ( water to water vapour )
When water evaporates , it's temperature decrease
2.this is because faster particles escape from the water's surface to become water vapour in the air.
3.when water evaporates from you body on sunny days, it carries Energy away..that is why you feel cooler.( Cooling effect )
Homework is given in work book pg.no : 86& 87
For better understanding of concepts watch the below videos