water, carbon, nitrogen cycles

The Water Cycle

water cycle- a never ending cycle of the Earth's waters

Water has three physical forms. They are gas (Water vapor), liquid (water), and solid (ice). Water in the atmosphere is usually in water vapor. Water that is falling is precipitation. If water is frozen it is solid. Precipitation can be rain, snow, sleet, mist, or hail.

Water when heated evaporates. Animals release water vapor through respiration. Pants release water vapor through transpiration.

The Carbon Cycle

Plants use carbon dioxide to produce sugar during photosyntheisis. To release the energy in the food organisms break down carbon compounds. Carbon is released through respiration.

The Earth's oceans contain the most water. The csrbon is dissolved in water. Carboon is also deposited on the ocean floor die and decay. Large amounts of carbon are underground. plants and animals decay slowly into fossil fuels. The 3 types of fossil fuels are coal, oil, and natural gas. When they are burned combustion happens and returns to the environment. Carbon is a gas.

The Nitrogen Cycle

Almost four-fifths of the air is nitrogen gas. Yet you cannot use this nitrogen. Plants cannot use pure nitrogen. They can absorb certain nitrogen compounds. They take them in through their roots. Lightning is one source. A lightning strike breaks apart pure nitrogen and rain brings it down for plants to use.

A compound is two or more elements bound together.

A greater source is nitrogen fixing bacteria. The bacteria lives in oceans, soil, and on the roots of certain plants. Certain bacterias break down nitrogen compounds into pure nitrogen and returns it to the environment.