Hilary Sci 2.2 Water Cycle PDF

A Proces s e s of t h e w a t e r c y c l e v, Flipped classroom In Nature, water keeps changing between liquid water and water Watch a video...

A Proces s e s of t h e w a t e r c y c l e v, Flipped classroom In Nature, water keeps changing between liquid water and water Watch a video and answer vapour. Water goes round and round between the land, the sky and the questions. the sea. The way water circulates in Nature is called the water cycle*. The figure below shows the main processes in the water cycle. © 2 Condensation | & As the upper part of the sky is anmaton cooler, the water vapour cools down and condenses to form small clouds (fresh water) water droplets. The water droplets join together to form clouds. 1 Evaporation water vapour Energy from the sun drives the water cycle. Evaporation occurs when sunlight warms the surface of the water. Water particles near the water surface absorb energy and move more quickly. They finally escape from the water surface to become water vapour. BE v te —————————————————" —————— ET ——— Sr - -— sea (salty water) Be I ET rT rr EY I RE 1 FET AY ATI AAAAAcidAA SAA AAs SA SEAL MATAR LAT RA RINT RITA PPC rr rr IIY Tr FP I SL I POPPER A Pr ep 1 13 LL AA a 3 11 LJ IRL 22 A003 ATTApla dA LAGE a etd ZEEE BAC RAL IA CR LL dgbe CO lid bid ERdd Sa d Sth SEES SAL SSEBN GLE ANAS S RAE, SAR, [oT Vol fa Ad Sit SH 2 AA SR Sie ATE20 Re pSanid iE So SSSR old Se Aa A paid AAASA anda Skt add TIAL 2 SIT ART ELF HTN PTY TTT LY SreRsravas PR er ags LE SEES EE EE EE RE \ 02 water cycle 7K1&3  i Water cycle 4 Precipitation Precipitation* forms in the clouds when « The ocean covers about 70% of the Earth's surface and holds about water vapour condenses and forms bigger , 97% of the total water on Earth. and bigger water dr oplets. When the Most precipitation (about 78%) droplets are heavy enough, they fall as occurs over it. Precipitation usually decreases with increasing distance rain. If clouds are at higher altitudes” and from the ocean. are colder, the water droplets may freeze to form ice. 3 Transportation Clouds may be carried to other places by wind. rain (fresh water) y 4d i A Sid A y oFa sno (fresh water) Z 8 J a \ Big science ideas Change and constancy in the water cycle In the water cycle, water keeps river (fresh wate changing between liquid water and water vapour. However, the total amount of water on Earth remains constant. lake (fresh water)  Key point p esses: : The water cycle involves thee following pro ae WE apc NE = condensation _ e "prociphistion i lB cseam—— CI IT Write ‘T’ for a true statement and ‘F’ for a false statement in the boxes provided. 1 Boiling is not involved in the water cycle. 2 Clouds are made up of water vapour. Check your answers (p: 162) (33 Rate of evaporation When we hang wet clothes for drying, we often unfold the clothes to make them dry more quickly. Why do wet clothes dry more quickly when they are unfolded? This is because the rate of evaporation” of water is higher when the surface area exposed to air is larger. -.ai % - — — te. STS SASEAREAAA Unfold the wet clothes N * = to make them dry ) more quickly. / pS Tha Sh ——— Tere pre ila Ti Koi hy TT). CEN 1g (a oa Fig 2.13 Wet clothes dry more quickly when they are unfolded Besides the surface area exposed to air, what other factors affect the rate of evaporation of water? Let us examine this in Practical 2.3. EE EEE AL ARLES Edd TT TL FL LL LR Lr YT TTT I LE rT LRT TT TT rT A pppoe rr rr CTL LE EEE EER EE LEE rate of evaporation ZZ2 %  WE. 1iio kL ORONO. Tres 1. 1121-114 W 1 In which of the following conditions will wet 2 The following containers hold the same clothes dry slowly? amount of water and are left under the sun. (1) Folding the clothes After several hours, which container would (2) Low humidity have the least amount of water? (3) Exposing to sunlight A B A (1) only B (1) and (2) only C (1) and (3) only D (2) and (3) only [] p: sip. Check your answers( 162) 4 Li Sectionlsummarye ZA 1 The water cycle involves the following processes: Evaporation Condensation Water in the sea, rivers and The water vapour cools down on land evaporates and and condenses, forming becomes water vapour. clouds. Precipitation Transportation Water droplets in the cloud Clouds may be carried to fall as rain. other places by the wind. @2 The rate of evaporation of water is higher when e the surface area exposed to air is larger, e the humidity is lower, e the temperature is higher, o the air speed is higher. 102  | 212E ECHONL cS ETC RBA NM IS Ao a SA... Ae Questions 1 to 3: Refer to the information below. Write ‘“T’ for a true statement and ‘F’ for a false statement in the boxes provided. Joe prepar es th e se t- up on th e ri gh t. Th e se t- up is |La0 i i=. EN 2 Rg 4 Err I Af te r se ve ra l ho ur s, li qu id Pi s |g] : gre eis “ t. ee tL S87 mS | eraser placed under th e su n. NS Wl CONS E collected in the glass. 1 The formation of liquid P involves boiling and condensation. [ &p. 95 2 Liquid P is colourless. €p. 95 @3 Liquid P can be collected in the glass more quickly when the coloured water is heated. [ &p. 95 @4 Grace finds that it takes a long time to dry her hair without using a hairdryer. a Give TWO reasons to explain why wet hair dries more quickly under hot hair from a hairdryer. (2 marks) b Grace usually separates her hair with her fingers when using the hairdryer. Explain why. (1 mark) &p. 107 103