Page 159 - Grasp English B2 (Student Book)
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Science Extinction of Dinosaurs
B. Answer the questions. Project
1. When are dinosaurs believed to have D. Work in a group of three and
become extinct? make an erupting volcano.
2. What percentage of the Earth was affected
by that mass-extinction event? Materials
3. What evidence is there to support the 3 cups of flour
idea of a meteor causing the dinosaurs’ 1 cup of salt
extinction?
1 cup of water
4. Why do some scientists believe the theory of 30 ml of oil
a huge volcanic eruption is more likely?
a large tray, with sides
1 small glass
C. Discuss with a partner.
2 tablespoons baking soda
1. What do you know about these other natural 1 teaspoon washing-up liquid
disasters? red and yellow food colouring
a) tsunami 30 ml of vinegar
b) earthquake
c) hurricane Instructions
d) drought
e) forest fire 1. Mix the flour, salt, water and oil together to make a
2. Where in the world are they more common? dough. If the dough is too hard, add a little more
water. If the dough is too watery, add a little more
3. What can be done to protect people,
animals and buildings against these flour.
disasters? 2. Put the dough onto the tray and put a glass into the
centre of it. Mould the dough around the glass to
make the neck of your volcano. When the dough is
dry, you can paint your volcano. Leave the paint to
dry overnight.
3. Make sure the volcano is completely dry and put the
baking soda into the glass. Put a few drops of both
red and yellow food colouring into the glass, too.
Adding a teaspoon of washing-up liquid will make
your volcano foam.
4. When you’re ready for your volcano to erupt, pour in
the vinegar and watch the result!
So now you know what happens when you mix
baking soda (sodium bicarbonate) with vinegar
(acetic acid).
Do you know which gas is given off during this
chemical reaction? The gas involved escapes as
bubbles, so the detergent in your volcano helps to
form those bubbles. If you could collect this gas, it
could be used as a simple fire extinguisher because
the gas is heavier than air. The gas displaces air and
starves a fire of the oxygen it needs to burn.
The gas is .
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