Unit 13 The Water Planet教案
here are some more familiar phenomena, what property of water are they related to?
the coastal areas are often neither too hot nor too cold.
ice floats on water.
when the sea water in a container is evaporated (蒸發(fā)), there will be some salt left.
irrigate in winter can help raise the soil temperature.
people swimming in the dead sea float; they can even read a paper while lying on their back in the water.
discussion: in the passage many properties have been talked about.are there any other properties you think important not mentioned?
homework: try to think as many examples as possible to show that water is made use of to bring benefit to human beings.
period 2 post-reading & listening
teaching goals:
1. to get students have a better understanding of water.
2. to learn some new words and sentence structures.
teaching procedures:
part one post-reading
i. better understand the properties of water
1. “where there is water, there is life!” can you use some facts to illustrate it?
－water is a medium for life.
so far as we know, life only exists on earth, because there is water. etc.
2. our planet is a water planet of which two thirds of its surface is covered by water. what’s more, our body is also mainly composed of water. do you know following figures which show how much water there is in parts of our body? 60%, 70%, 82%, 90%
up to _____ of the human body is water.
______ of the brain is composed of water.
______ blood is made up of water.
the lungs are nearly _____ water.
3. water is the source of life. that’s why water is an excellent medium for life. and you know all this is because of water’s unique properties.
ii. revision on the properties of water
1. what are the properties of water?
water is polar.
water is liquid at room temperature.
water has a relatively high freezing point.
water has density 1,000 kg/m3.
water has high heat capacity.
…
2. what causes water to have such unique properties?
－it’s molecule form / chemical structure.
3. what is water molecule like?
chemical structure: two hydrogen atoms and one oxygen atom.
different parts of it: a slightly positive end and a slightly negative end, so it is polar.
the function of it: it causes water to be able to dissolve both solids and gases, and that’s why water can break down nutrients quickly.