Cycles Respiration, Photosynthesis, Evaporation and Condensation, The Weathering of Rock, and the Decay of Organic Matter

Evaporation What is it? – Evaporation- the process of when water is heated up and changes from liquid to a gas (water vapor). Water vapor- a visible exhalation, as fog, mist, or steam diffused through or suspended in the air. Where does water vapor occur? – Studies have shown that the oceans, seas, lakes, and rivers provide nearly 90 percent of the moisture in the atmosphere via evaporation, with the remaining 10 percent being contributed by plant. – A very small amount of water vapor enters the atmosphere through sublimation, the process by which water changes from a solid (ice or snow) to a gas, bypassing the liquid phase. This often happens in the Rocky Mountains. Why does this occur? – Energy from the sun heats up our surface water causing evaporation. – The process of evaporation removes heat from the environment, which is why water evaporating from your skin cools you. – It is part of the water cycle

Condensation CONDENSATION What is it? – Condensation- the process of when water vapor cools down and turns back into liquid form. Water molecules will combine with tiny particles of dust, salt, and smoke in the air to form cloud droplets, which grow and develop into clouds, a form of water we can see. Where does it occur? – Condensation is responsible for ground-level fog, for your glasses fogging up when you go from a cold room to the outdoors on a hot, humid day, for the water that drips off the outside of your glass of iced tea, and for the water on the inside of the windows in your home on a cold day. – Cloud-like trails that high-flying airplanes leave behind Why does this occur? – Heat is released into the atmosphere as a result. – Water vapor is cooled and creates clouds. – It is part of the water cycle.

Respiration What is it? – Respiration is – Where does respiration occur? Why does this occur? Occurs at all times in cells Releases energy from sugar Complex substances (sugar) are broken down into simpler ones. Carbon dioxide and water are the waste products. Oxygen is taken in

Photosynthesis What is it? – Photosynthesis is the process by which plants make food – Where does photosynthesis occur? – It occurs in plants – This cycle of photosynthesis and respiration maintains the balance of carbon dioxide and oxygen on earth. Why does this occur? – Occurs in the presence of light (and chlorophyll in plant cells) – Requires energy (light) to make sugar (glucose) – Complex substances (sugar) are formed from simpler ones. – Carbon dioxide and water are the raw materials. – Oxygen is given out.

Weathering of Rock What is it? Weathering of Rock- Weathering general term that encompasses variety of processes that decompose rock: · Mechanical weathering-movement of rocks · Chemical weathering loss of minerals from rocks and soils due to reactions with acidic and oxidizing· Usually involves water, followed by release of dissolved ions available for uptake by biota or loss in runoff Where does Weathering of rocks occur? The process of chemical weathering generally occurs in the soil where water and minerals are in constant contact. Agents of weathering are oxygen, air pollution, water, carbonic acid, and strong acids. They combine with the minerals in rocks to form clays, iron oxides, and salts, which are the endpoints of chemical weathering. Why does this occur? Water plays a very important role in chemical weathering in three different ways. First, it combines with carbon dioxide in the soil to form a weak acid called carbonic acid. Microbe respiration generates abundant soil carbon dioxide, and rainwater (also containing atmospheric carbon dioxide) percolating through the soil provides the water. Carbonic acid slowly dissolves away minerals in rock, especially the carbonate minerals that make up limestone and marble. The weak acid decomposes the insoluble rock into water soluble products that move into the groundwater. In high concentrations, these dissolved minerals can cause the water to be considered "hard." Second, water can hydrate minerals by being adsorbed onto the mineral lattice. The conversion of anhydrite into gypsum is an example. Finally, the water can break up minerals through hydrolysis. The most common group of minerals, the silicates, is decomposed by this process. Reactive hydrogen ions that are liberated from the water attack the crystal lattice, and the mineral decomposes. Read more: Weathering of Rocks - river, sea, oceans, temperature, important, salt, system, oxygen of Rocks - river, sea, oceans, temperature, important, salt, system, oxygen

Decay of Organic Matter What is it? – Decay of Organic matter (putrefaction) plants and small animals eat once lived tissue as a source of nutrition – Where does Decay of organic matter occur? On the ground level when plants die They release nitrogen into the environment for high plants. Why does this occur? – Helps other plants grow