SUBLIMATION
Change of solid directly into vapours on absorbing heat.
ICSE
FORCE OF ADHESION
The force of attraction between the molecules of two different substance is called “FORCE OF COHESION” i.e. between glue and paper.
FORCE OF COHESION
The inter-molecular force of attraction between the the molecules of the same substance called “FORCE OF COHESION.” i.e. water and water.
WHAT IS INTER- MOLECULAR FORCE ?
The molecules of a matter exert a force of attraction on each other . The force of attraction is called inter molecular force.
What is Matter ?
Matter is something which has mass, occupies space, and can be perceived by our senses .Hydrogen , milk ,pen etc.
Question 10.
How does temperature, light intensity and wind affect transpiration?
Answer:Temperature: Transpiration is faster on hot summer days as compared to cold winters.Light intensity: The transpiration rate is increased due to the increase in light intensity.During daytime in the sunlight, the rate of transpiration is faster. This is because thestomata remain open to allow the inward diffusion of carbon dioxide for photosynthesis.During dark, the stomata …
Question 10.
How does temperature, light intensity and wind affect transpiration? Read More »
Question 9. Briefly explain, how transpiration helps in upward conduction of water in plants? (a) ………. (b) ……….
Answer:(a) Plants continuously absorb water through their roots. This water is sent up throughthe stem to all parts of the plant, including the leaves. Only a little amount, of water isretained in the plant or utilised by it in photosynthesis. The rest of it gets evaporated intothe atmosphere as water vapour through the stomata present …
Question 6.
Under what conditions do plant transpire (a) more quickly and (b) most slowly?
Answer:(a) Transpiration is faster on hot summer days as compared to cold winters.(b) Transpiration is reduced if the air is humid. Air cannot hold any water moleculeswhen it is already laden with moisture (humidity).
Question 5.
Define the terms:
(a) semi-permeable membrane
(b) osmosis
Answer: (a) Semi-permeable membrane: It is a membrane that allows the movement of solventmolecules (e.g. water molecules) through it but prevents the movement of soluteparticles (e.g. sugar or salt molecules).For example: Egg membrane, parchment membrane, cellophane paper etc. are semi-permeable membranes. (b) Osmosis: The diffusion of water molecules through a semi-permeable membranefrom a region where …
Question 5.
Define the terms:
(a) semi-permeable membrane
(b) osmosis Read More »