2 George is studying strategies to reduce environmental problems. He learns that moving to a low-carbon economy is important. What is a low-carbon economy? A An economy that uses only coal B An economy that minimizes carbon emissions C An economy that relies on oil D An economy that uses no energy
4 Which layer of atmosphere is important for radio communication? A Troposphere B Stratosphere C Ionosphere D Mesosphere
5 Uma is studying water treatment. She knows that coagulation involves the addition of chemicals. What is the purpose of adding alum in coagulation? A To add minerals B To neutralize acids C To make suspended particles clump together D To kill bacteria
7 Quinn is studying ways to deal with water pollution. He knows that planting trees can help. How does planting trees help in reducing water pollution? A By increasing runoff B By reducing soil erosion and runoff of pollutants C By decreasing water availability D By increasing fertilizer use
8 Victor is studying the quality of water from natural resources. He knows that groundwater is often cleaner than surface water. What is a disadvantage of groundwater? A It is always contaminated B It can contain high concentrations of dissolved minerals C It is always safe to drink D It does not contain any minerals
9 Rachel is studying waterborne diseases. She knows that jaundice is a waterborne disease. What is the cause of jaundice? A Bacterial infection B Viral infection affecting the liver C Fungal infection D Parasitic infection
10 Ahmed is studying the composition of the atmosphere in his chemistry class. He learns that the atmosphere is made up of several gases. Which gas is the most abundant in the Earth's atmosphere? A Oxygen B Carbon dioxide C Nitrogen D Argon
13 Which international agreement aims to protect the ozone layer? A Kyoto Protocol B Montreal Protocol C Paris Agreement D Geneva Convention
14 Ozone layer depletion increases: A Visible light reaching Earth B Infrared radiation C Ultraviolet radiation D Humidity
15 David is studying water treatment. He knows that raw water treatment involves multiple steps. What is the correct order of steps in raw water treatment? A Filtration, sedimentation, chlorination, coagulation B Sedimentation, coagulation, filtration, chlorination C Coagulation, sedimentation, filtration, chlorination D Chlorination, coagulation, sedimentation, filtration
16 Which property makes water suitable for life? A Low boiling point B High freezing point C Ability to dissolve substances D Low surface tension
17 George is learning about water pollution. He knows that plastics are a major pollutant in water bodies. What is a disadvantage of plastics in water? A They provide habitat for aquatic life B They degrade naturally and are harmless C They are non-biodegradable and harm marine life D They increase oxygen levels in water
19 Hardness of water is mainly due to the presence of: A Sodium salts B Calcium and magnesium salts C Potassium salts D Iron salts
20 Which parameter indicates the amount of salts dissolved in water? A pH B Hardness C TDS D Turbidity
21 Bilal is learning about air pollutants. His teacher explains that pollutants can be natural or man-made. Which of the following is a primary air pollutant released from the burning of fossil fuels? A Ozone B Sulfur dioxide C Water vapor D Nitrogen gas
22 Soft water is suitable for: A Drinking only B Washing and cleaning C Industrial cooling only D Agriculture only
23 Oliver is learning about waterborne diseases. He knows that typhoid is a waterborne disease. Which of the following is also a waterborne disease? A Malaria B Jaundice C Tuberculosis D Asthma
25 Hina is studying water scarcity in Pakistan. She knows that climate change is a factor. What is the effect of climate change on water availability in Pakistan? A It increases water availability B It causes glacial melt and changes in rainfall patterns C It has no effect D It decreases water demand
26 Hina is learning about international cooperation and politics. She understands that global environmental problems require cooperation. Which international agreement is focused on protecting the ozone layer? A The Paris Agreement B The Montreal Protocol C The Kyoto Protocol D The Geneva Convention
27 Carlos is studying allergens as air pollutants. He learns that allergens can cause allergic reactions. Which of the following is a common indoor allergen? A Pollen B Dust mites C Smog D Acid rain
28 Which household method improves drinking water quality? A Mixing chemicals B Boiling C Adding sugar D Shaking