Term 2 review: Earth’s resources and patterns in the sky
الأسبوع 30 · مراجعة الفصل الدراسي الثاني: الموارد الموجودة على سطح الأرض والأنماط في السماء · 3 دروس
2
Review: protecting resources
Discovery Education Science P5: Term 2, Units 3–4
GoalReview renewable and nonrenewable resources, ways to protect them, cleaner energy, water use, filters and solar stills with new questions.
New words
renewable · able to be replaced in a fairly short time, but it can still be used upconservation · using less and wasting nothingdesalination · taking salt out of sea water
Explanation
Natural resources are materials from nature that people use. Renewable resources, such as water, trees and fish, can be replaced, but they can run short if we use them faster than they come back or if we pollute them. Nonrenewable resources, such as oil, gas and coal, take millions of years to form. Conservation means saving and using wisely, preservation means keeping a place untouched, and restoration means repairing damage. Cleaner air comes from sources that do not burn fuel, such as wind in Zafarana and sunshine at Benban. We can work out how much water we use by multiplying minutes or times by litres. A filter of sand, charcoal and cotton makes cloudy water look clearer but not safe to drink. Wastewater engineers clean used water so it can irrigate farms. A solar still uses the Sun’s heat to evaporate salt water, and the vapour condenses on a cooler cover and drips into a cup as fresh water.
Idea
Example
renewable
fish, if not over-fished
nonrenewable
oil and gas
conservation
turn off a tap
preservation
a protected reef
restoration
replant palms
Worked examples
Habit
Family’s water a day
tap running
160 L
tap off
10 L
A family of 5 brushes teeth twice a day for 2 minutes each time, with the tap running at about 8 L every minute. Per person per day: 2 × 2 × 8 = 32 L. For all 5: 5 × 32 = 160 L. If they turn the tap off, each brushing uses about 1 L, so a person uses 2 L a day and the family 10 L. They save 160 − 10 = 150 L a day.
A solar still collects 15 mL each hour in strong sun. In 5 hours it collects 5 × 15 = 75 mL. The water is measured, never tasted. A spoon test (crystals when dry) shows if salt got in.
1200 L cleaned→3 farms: 900 L→park: 300 L
A treatment tank cleans 1200 L of used water. Three farms take 300 L each: 3 × 300 = 900 L. The rest, 1200 − 900 = 300 L, goes to a park. The cleaned water does not go to drinking taps.
Class activity
Resource sort. Write 12 cards (renewable and nonrenewable resources, and actions such as “turn off a tap”, “protected reef”, “replant palms”). Sort the resources into renewable and nonrenewable, and the actions into conservation, preservation and restoration. Ask a friend to check. Then write one thing your family can do to save 20 litres of water a day.
Practice
1
Sort these into renewable or nonrenewable: wind, coal, fish, natural gas.
