Science Unit B ch. 1 Ls. 1 How does nature reuse materials? 1.) Natural Cycles 1.)Materials on Earth reused by living organisms Ex: Minerals in rocks released through erosion into water  Animal drinks water and takes in minerals  > Animal wastes and puts minerals back into soil>  Plants get materials from soil and release into air through photosynthesis>  Plants and animals die/decay putting more materials into soil.

2.)The Nitrogen Cycle 2.) Earth’s atmosphere 78% nitrogen > Nitrogen is “fixed” through lightening and soil > Plants get Nitrogen as nitrates and ammonia >Animals eat plants and get nitrogen/protein >Animal waste and urine returns ammonia to soil >Animals/Plants die/decay and put ammonia back into soil.

3.)Carbon Dioxide- Oxygen Cycle 3.)Plants>Animals>Environment Photosynthesis-Plants using sun, water, and carbon dioxide as food and release oxygen. Respiration-animals and plants “breathing” oxygen and releasing carbon dioxide Decay-Dead plants and animals-bacteria eat carbon as food and release extra into air. Fossil fuels-decayed animal fossils over millions of years turns carbon into petroleum. Carbon in plants becomes coal. Sunlight-provides energy for plant photosynthesis Combustion-using oxygen in factories to burn fossil fuels and releases carbon dioxide

4.)Changing Balance 4.)-Problems: More people = more factories, cars, airplanes, etc…= more fuels, wood, and coal needed to run factories and motors. We are cutting down more trees and mining more areas to get more fuel and make room for homes and buildings. Since we have less trees to use up the extra carbon dioxide, we are getting too much in our air and it can poison animals and humans and weaken our atmosphere.

Science Unit B Ch 1 Ls 2-Water 1.) Water Cycle 1.) How Earth Recycle’s water Evaporation- Sun’s heat turns water into water vapor that floats upward. Evaporation- Sun’s heat turns water into water vapor that floats upward. Condensation-Water vapor in sky turns back into liquid water droplets that stick together to form clouds Condensation-Water vapor in sky turns back into liquid water droplets that stick together to form clouds Precipitation- The clouds get heavy and, depending on the air temperature, moisture falls as rain, sleet, snow, or hail. Precipitation- The clouds get heavy and, depending on the air temperature, moisture falls as rain, sleet, snow, or hail.

2.) Other Water on Land/Air 2.) Runoff-Excess rain, that doesn’t soak into the soil and become groundwater, runs back into rivers. Transpiration-Moisture from plants from their stomata and from animals from their lungs and urine. Transpiration-Moisture from plants from their stomata and from animals from their lungs and urine.

3.) Earth’s water 4.) Human Impact on Water 3.) ycle/index.html 4.) Need more every year for drinking, cooking, bathing, agriculture, animals, make plastic, paper, aluminum… -Limited freshwater because so much is frozen in ice caps/glaciers. -Rainwater washes harmful chemicals like oil into lakes and rivers, fertilizers/pesticides into soil and groundwater. We have to use expensive water treatment techniques to clean water again. -We can help by recycling used motor oil so it doesn’t go into soil, use washers and toilets that don’t use too much water, washing clothes and dishes only as a full load, and planting plants that don’t require as much watering.