a) State four (4) ways of controlling mosquitoes in the community. b) Give four (4) measures that can be taken to minimize the negative impact of gold extraction on the Ghanaian environment. c) State

You're on a roll — here are the solutions to questions 6, 7, and 8: 6. a) State four (4) ways of controlling mosquitoes in the community. • Eliminate stagnant water bodies where mosquitoes breed. • Use insecticide sprays or larvicides in breeding areas. • Encourage the use of mosquito nets, especially treated ones. • Promote proper waste management to prevent water collection in discarded items. b) Give four (4) measures that can be taken to minimize the negative impact of gold extraction on the Ghanaian environment. • Implement strict environmental regulations and enforce them rigorously. • Reclaim and reforest mined-out areas to restore vegetation. • Treat wastewater from mining operations before discharge to prevent water pollution. • Promote the use of environmentally friendly mining technologies that reduce chemical use (e.g., mercury). c) State four (4) importance of cover cropping in crop production. • Soil erosion control: Cover crops protect the soil surface from wind and water erosion. • Weed suppression: They outcompete weeds for light, water, and nutrients. • Soil fertility improvement: Leguminous cover crops fix nitrogen, and all cover crops add organic matter to the soil. • Moisture retention: They help reduce evaporation from the soil surface, conserving moisture. d) State two (2) uses of each of the following i) Metals • Used in construction (e.g., steel for buildings, iron for bridges). • Used for electrical wiring (e.g., copper, aluminum). ii) Non-metals • Oxygen is essential for respiration in living organisms. • Carbon (as coal or natural gas) is used as a fuel source. 7. a) i) Define light energy. Light energy is a form of electromagnetic radiation that is visible to the human eye and travels in waves. a) ii) Explain two (2) ways in which light energy is useful to living organisms. • Photosynthesis: Plants and other photosynthetic organisms use light energy to convert carbon dioxide and water into glucose (food) and oxygen. • Vision: Animals use light energy to perceive their surroundings, allowing them to navigate, find food, and avoid predators. b) i) Define an atom. An atom is the smallest unit of an element that retains the chemical identity of that element, consisting of a nucleus surrounded by electrons. b) ii) An atom has 11 electrons. a) Draw the electronic configuration of the atom. The electronic configuration is 2, 8, 1. b) Type of bond the element will form with chlorine. The element (Sodium, Na) will form an ionic bond with chlorine. c) Give two (2) reasons for the type of chemical bond stated in (β) above. • There is a large difference in electronegativity between sodium (a metal) and chlorine (a non-metal). • Sodium transfers its valence electron to chlorine, resulting in the formation of stable ions (Na^+ and Cl^-) with full outer shells. c) i) Define food poisoning. Food poisoning is an illness caused by consuming food contaminated with harmful bacteria, viruses, parasites, or their toxins. c) ii) Explain two causes of food poisoning. • Improper cooking: Food that is not cooked to the correct temperature may not kill harmful bacteria or viruses. • Cross-contamination: Pathogens can transfer from raw foods (like raw meat) to ready-to-eat foods if not handled properly. d) State two (2) methods of soil conservation. • Contour plowing: Plowing across the slope of a hill rather than up and down to reduce water runoff and erosion. • Crop rotation: Alternating different crops in the same field over successive seasons to maintain soil fertility and reduce pest buildup. 8. a) i) State the law of floatation. The law of floatation states that a floating object displaces a weight of fluid equal to its own weight. a) ii) Explain how a submarine operates. A submarine operates by changing its buoyancy. It has ballast tanks that can be filled with water to increase its overall density, causing it to dive. To surface, compressed air is used to force water out of the ballast tanks, decreasing its density and allowing it to rise. b) i) State three (3) ways of preventing dental decay. • Brush teeth regularly (at least twice a day) with fluoride toothpaste. • Limit the consumption of sugary foods and drinks. • Floss daily to remove food particles and plaque between teeth. b) ii) State one (1) cause each of: a) Constipation: One cause is insufficient fiber in the diet. b) Indigestion: One cause is eating too quickly or consuming fatty/spicy foods. c) i) What is an alloy? An alloy is a mixture of two or more elements, at least one of which is a metal, combined to create a new material with enhanced properties. c) ii) Name the main elements present in each of the following: a) Bronze: Copper and Tin b) Nichrome: Nickel and Chromium (often with Iron) c) Duralumin: Aluminium, Copper, Magnesium, and Manganese d) i) List two (2) types of animal parasites. • Endoparasites (e.g., tapeworms, roundworms) • Ectoparasites (e.g., ticks, fleas) d) ii) State three (3) economic importance of the grasshopper. • Crop damage: Grasshoppers are significant agricultural pests that can destroy crops, leading to substantial economic losses for farmers. • Food source: They serve as a food source for various animals, contributing to the food chain and supporting biodiversity. • Bait: Grasshoppers are sometimes used as bait for fishing. That's all the questions from this page! What's next?