Here are short and accurate answers: *(a)(i)* 1. Switch off lights when not in use 2. Use energy-efficient bulbs 3. Unplug devices when fully charged *(a)(ii)* Energy = Power × Time = 4000 W × 12 h = *48,000 Wh* or *48 kWh* *(b)(i)* 1. Litmus 2. Methyl orange *(b)(ii)* - Litmus: red in acid, blue in base - Methyl orange: red in acid, yellow in base *(c)(i)* 1. Reforestation 2. Recycling 3. Use of clean energy 4. Sustainable farming *(c)(ii)* 1. Carbon dioxide (CO₂) 2. Methane (CH₄) *(d)* Collect kitchen waste, dry leaves, mix with soil, turn regularly to decompose. *(a)(i)* 1. Fish meal 2. Milk *(a)(ii)* 1. Maize 2. Cassava *(b)* Evaporation → Condensation → Precipitation → Collection *(c)(i)* - Air: Oxygen, nitrogen - Vinegar: Water, acetic acid *(c)(ii)* - Solvent: - Air: Nitrogen - Vinegar: Water *(d)(i)* 1. Extreme cold 2. Lack of oxygen *(d)(ii)* 1. Saturn 2. Neptune *(e)(i)* Sharp edge reduces surface area, increasing pressure for easy cutting *(e)(ii)* P = F/A = 10 N / (1 × 10⁻³ m²) = *10,000 N/m²* *(f)* 1. Collect soil sample 2. Mix with distilled water 3. Insert pH paper or probe 4. Compare color with chart or read value *(g)(i)*