1.1 Chemicals in the Environment
Trees, mountains, the air we breathe, our own bodies—everything that makes up the environment is made of chemicals. All living things are made of chemicals and depend on chemicals to survive. Without carbon dioxide and water, green plants could not produce sugar for food. Without oxygen, plants and animals could not carry out cellular respiration. These are just a few of the chemicals that support living things.
|
|
Nitrogen & Carbon Cycle
|
Nitrogen is required for plants to make substances necessary for life. BUT, plants can't actually use the nitrogen on it's own. It has to be "fixed" to another element, forming compounds. This is called Nitrogen Fixation.
|
PollutionPollution is any change in the environment that produces a condition that is harmful to living things. For example, smog caused by vehicle exhaust emissions is pollution because it makes it hard for people and other animals to breathe. Forest fires produce similar chemical pollution.
|
|
1.2 Acids & Bases
|
An acid is a compound that dissolves in water to form a solution with a pH lower than 7. The pH number of a solution indicates its acidity. It is a measure of the concentration of hydrogen ions in a solution.
A base is a compound that dissolves in water to form a solution with a pH higher than 7.
|
1.3 Organic Compounds
Complex molecules that contain carbon, they are called organic compounds. Our bodies need about 25 elements for normal growth. Carbon (C), oxygen (O), and hydrogen (H) are the most common chemical elements in living things. Together, they make up the complex molecules that form sugar, starch, fat, oil, wax, and proteins. Fossil fuels (petroleum, natural gas, and coal) are examples of substances that contain many different organic compounds. Substances that do not contain carbon are called inorganic compounds. Baking soda and the mineral quartz are examples of inorganic compounds.
|
|