(a) Definition of environmental balance: lt is the stable state of matter and energy within an ecosystem. OR It is the stability and sustainability of the natural ecosystem through recycling of material matter and energy flow. OR Ways of recycling matter and the stable flow of energy within an ecosystem.
(b) Water Cycle:
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- It is the natural exchange of water between water bodies atmosphere, land, and living things.
- Water evaporates when it warms up.
- It evaporates from water bodies, land, and forest.
- Atmosphere receives water vapor from land, rivers, oceans, etc.
- Atmosphere also receives water vapour from transpiration of plants.
- Condensed water droplets coalesce form clouds.
- Clouds release precipitation rainfall to land, water bodies, and living things.
- The rainwater returns, to water bodies through runoff and underground water.
- Water returns to the atmosphere again to complete the cycle.
(b) Water cycle:


[b](c) Ways in which the water cycle is beneficial to man:
- All living things (organisms) require water for life /hydration.
- Water is important for weathering of rocks to form soils for agriculture
- Underground water serves as a reservoir of water for man to harness through wells and boreholes.
- Water is necessary for photosynthesis through which plants produce food for man.
- Underground water feeds springs and streams.
- Loss of water by transpiration aids the cooling of plants.
- Rainfall provides water for domestic uses
- Rainfal provides water for industrial uses.
- Water from rivers aid the generation of hydroelectric power.