Key Scientific Concepts: Chemistry, Biology, Environment

Essential Scientific Vocabulary

• Nitrogen Fixation: Any process that causes nitrogen to combine with other elements to form compounds such as ammonia, nitrates, and nitrites.
• Neutralization: The process of adding an acid and a base together to achieve a neutral pH.
• Macronutrients: Nutrients that we need in larger quantities to provide us with energy.
• Micronutrients: Vitamins and minerals needed by the body. A deficiency or surplus of them can cause severe health issues.
• Carbohydrates: Sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks.
• Lipid: Organic fats that are insoluble in water.
• Osmosis: The movement of molecules through a selectively permeable membrane.
• Hydrolysis: A chemical reaction where one water molecule breaks one or more chemical bonds.
• Substrate: The base on which an organism lives.
• LD50: (Lethal Dose 50%) The amount of a substance required to kill 50% of a test population.
• Leachate: A liquid that has passed through something and has accumulated waste from it.
• Biodegradation: The breakdown of organic matter by microorganisms.
• Aerobic and Anaerobic Biodegradation:
  • Aerobic: Breakdown of organic materials with air (oxygen).
  • Anaerobic: Breakdown of organic materials without air (oxygen).
• Phytoremediation: The use of plants to clean up waste that would be very difficult or impossible to clean up otherwise.
• Biomagnification: The increase in concentration of a chemical or element as it moves up the food chain.
• Bioaccumulation: The increase in concentration of a chemical or element within a single organism over time, similar to biomagnification but within one species.
• Ingestion: The process of taking in food or nutrients by swallowing or absorbing it.
• Chlorofluorocarbons (CFCs): Nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine.
• Dispersion: The action or process of distributing things or people over a wide area.
• Dilution: The action of making something weaker or less concentrated by adding water or another solvent to it.

Understanding Acids and Bases

The pH Scale and Litmus Test

• The pH Scale: Ranges from 0 to 14.
  • 0-6: Acids
  • 7: Neutral
  • 8-14: Basic/Alkaline
• Litmus Test:
  • Blue litmus turns red if the solution is acidic.
  • Red litmus turns blue if the solution is basic.

Causes and Effects of Acid Rain

Acid rain is caused when sulfur dioxide and nitrogen oxides are released into the air, making precipitation more acidic. This phenomenon occurs when sulfur compounds and nitrogen compounds mix with atmospheric moisture.

If acid rain persists, it can cause significant damage to buildings, natural environments, and vehicles.