AP Environmental Science Unit 0: Introduction

Matter

anything that occupies space and has mass.

Mass

a measure of the amount of matter in an object.

Weight

the force that results from the action of gravity on mass.

Radioactive Decay

the spontaneous release of material from the nucleus. changes the radioactive element into a different element. emits a great deal of energy that can be captured as heat and is used by nuclear power plants.

Half-Life

the time it takes for one half of the original radioactive atoms to decay.

Covalent Bonds

elements that do not readily gain or lose electrons form compounds by sharing electrons.

Atom

smallest unit of matter. nucleus (protons and neutrons) and shell (electron).

Ionic Bonds

involves the transfer of electrons. one atom becomes positively charged, and the other becomes negatively charged. this charged imbalance holds the atoms together.

Hydrogen Bonds

a weak chemical bond that forms when hydrogen atoms that are covalently bonded to one atom are attracted to another atom on another molecule.

Polar Molecule

one side is more positive and the other more negative.

Acid

a substance that contributes hydrogen ions to a solution.

Base

a substance that contributes hydroxide ions to a solution.

Chemical Reaction

occurs when atoms separate from the molecules they are part of or recombine with other molecules.

Law of Conservation of Matter

matter can't be created or destroyed; it can only change forms.

Surface Tension

results from the cohesion of water molecules at the surface of a body of water and creates a sort of skin on the water's surface.

Capillary Action

happens when adhesion of water molecules to a surface is stronger than cohesion between the molecules.

Inorganic Compounds

compounds that either (a) do not contain the element carbon or (b) do contain carbon, but only carbon bound to elements other than hydrogen.

Organic Compounds

compounds that have carbon-carbon or carbon-hydrogen bonds.

Carbohydrates

compounds composed of carbon, hydrogen, and oxygen atoms. for example, glucose is used for quick energy.

Proteins

made up of long chains of nitrogen-containing organic molecules called amino acids.

Enzymes

proteins that help control the rates of chemical reactions.

Nucleic Acids

organic compounds found in all living cells (DNA and RNA).

DNA

genetic material that is the code for reproducing components.

RNA

translates the code stored in the DNA and allows for the synthesis of proteins.

Lipids

smaller biological molecules that don't mix with water and form a major part of the membranes that surround cells.

Electromagnetic Radiation

a for of energy that includes visible light, UV light, and infrared energy.

Photons

massless packets of energy that travel at the speed of light and can move even through the vacuum of space. the amount of energy contained depends on its wavelength.

Energy

ability to do work. power x time.

Power

the rate at which work is done. energy/time.

Chemical Energy

potential energy stored in chemical bonds.

First Law of Thermodynamics

energy cannot be created or destroyed (law of conservation of matter).

Second Law of Thermodynamics

when energy is transformed, the quantity of energy stays the same, but its ability to do work diminishes.

Energy Efficiency

the ratio of the amount of work that is done to the total amount of energy that is introduced into the system in the first place. output/input.

Energy Quality

the ease with which an energy source can be used for work.

Open System

exchanges of matter or energy occur across system boundaries.

Closed System

matter and energy exchanges across system boundaries do not occur.

Adaptive Management Plan

a strategy that provides flexibility so that managers can modify as future changes occur.

Atomic Mass

the number of neutrons and protons in the nucleus of an atom.

Atomic Number

the number of protons in the nucleus of an atom.

Isotope

two or more atoms with the same atomic number but different atomic mass.

Molecule

made up of 2+ atoms - same or different.

Combustion Reaction

hydrocarbons. EG: CH4+O2 -> Energy + (*CO2 + H2O ALWAYS)

Temperature

the measure of the average kinetic energy of a substance.

Entropy

the amount of energy in a system that is thermal (heat) energy that is unavailable to do work.

Chemosynthesis

a process by which some organisms use chemical energy to produce carbohydrates.

Steady State

(in a system) when output equals input.

Negative Feedback Loops

when a system responds to change by returning to its original state, or at least by decreasing the rate at which the change is occuring.

Positive Feedback Loops

when a system responds to change by exacerbating the effects of a small disturbance.