الأسبوع 18 · المحور الثالث، الوحدة الثالثة، المفهوم 3.2 «الوقود وأنواعه» (أ): أنواع الوقود ومن أين تأتي · 3 دروس
3
Renewable or nonrenewable?
Discovery Education Science P4: Term 2, Unit 3, pp. 26–39
GoalCompare oil and water as resources, tell renewable from nonrenewable resources and suggest ways to conserve.
New words
renewable resource · a natural material that can be replaced soon after it is usednonrenewable resource · a natural material used faster than it can be replacedconserve · to use less so that a resource lasts longer
Explanation
Oil and water are two resources that people use to make power. Oil comes from deep underground. It formed over millions of years from the remains of tiny sea living things, pressed under layers of mud and rock. We use oil far faster than new oil forms, so oil is a nonrenewable resource and we could run out of it. Water is different. The water cycle brings it back again and again: water evaporates, forms clouds, and falls as rain. So water is a renewable resource. But we must still be careful: we should not waste water or pollute it, because clean water may not come back as fast as we need it. To conserve resources means to use them wisely: switch off lights, take the bus or share a car, close the tap, and repair leaks.
Worked examples
Farida asks: is oil renewable? It took millions of years to form and we use it much faster, so it is nonrenewable. Is water renewable? Rain brings it back, so yes, but we still save water.
12 people go to a football match. If each goes in their own car, that is 12 cars. If they share and 4 people ride in each car, 12 ÷ 4 = 3 cars. Sharing uses much less fuel.
Marwan turns off the tap while he brushes his teeth and switches off the light when leaving his room. He is conserving water and electricity.
Class activity
Save and sort. Make two lists with a grown-up. List A: resources that are renewable (for example sunlight, wind, water, plants if replanted). List B: nonrenewable (coal, oil, natural gas). Then write four ways your family can conserve fuel or water this week and tick them off.
Practice
1
Is oil a renewable or a nonrenewable resource? Why?
Nonrenewable: it forms over millions of years and we use it faster than it forms.
2
Why is water called renewable?
The water cycle brings it back as rain again and again.
3
Which two actions conserve resources? Say the letters.
Letter
Action
A
leaving the tap open
B
closing the tap
C
sharing a car
B and C: closing the tap and sharing a car.
4
20 students go on a trip. Each bus holds 40 students. How many buses are needed? How many cars with 4 students would be needed?
