APES summer

Environment

Sum of all conditions surrounding us that influence life.

Environmental science

Study of interactions among human systems and natural systems.

Ecosystem

A location with interacting biotic and abiotic components.

Biotic

Living components of an ecosystem.

Abiotic

Nonliving components of an ecosystem.

Environmentalism

A social movement to protect the environment.

Environmental studies

Environmental science plus policy, economics, literature, and ethics.

Sustainability

Using resources in a way that doesn't jeopardize future generations.

Scientific method

Objective way to explore nature, draw inferences, and predict outcomes.

Hypothesis

A testable conjecture about how something works.

Independent variable

The variable you change or control; not dependent on other factors.

Dependent variable

The variable you measure; depends on the independent variable.

Control group

Group with the same conditions as the experimental group except the one variable under study.

Natural experiment

A natural event that acts as an experimental treatment.

Replication

Taking repeated measurements.

Sample size (n)

Number of times a measurement is replicated.

Accuracy

How close a measured value is to the true value.

Precision

How close repeated measurements are to one another.

Uncertainty

Estimate of how much a measured or calculated value differs from the true value.

Inductive reasoning

Making general statements from specific facts or examples.

Deductive reasoning

Applying a general statement to specific facts or situations.

Theory

A hypothesis repeatedly tested and confirmed by multiple groups of researchers.

First law of thermodynamics

Energy is neither created nor destroyed, but can change form.

Second law of thermodynamics

When energy is transformed, its ability to do work diminishes.

Science

Attempt to discover how nature works and use that knowledge to predict outcomes.

Data

Information collected through observation and experiments.

Model

Approximate representation or simulation of a system.

Scientific law (law of nature)

Well-tested description of what repeatedly happens the same way in nature.

Peer review

Scientists publish their methods and results for evaluation by other experts.

Tentative (frontier) science

Preliminary results not yet widely tested or peer reviewed.

Reliable science

Data, models, theories, and laws widely accepted after testing and debate.

Unreliable science

Results presented as reliable without peer review.

Matter

Anything that has mass and takes up space.

Element

A unique fundamental type of matter that can't be broken down chemically.

Compound

Two or more different elements held together in fixed proportions.

Atom

Smallest unit of matter displaying an element's chemical properties.

Atomic theory

All elements are made of atoms.

Molecule

Two or more atoms held together by chemical bonds.

Ion

Atom or group of atoms with a net positive or negative charge.

Proton (p)

Positively charged particle in an atom's nucleus.

Neutron (n)

Particle with no charge in the nucleus of an atom.

Electron (e)

Negatively charged particle outside the nucleus.

Nucleus

The tiny center of an atom containing protons and neutrons.

Atomic number

Number of protons in an atom's nucleus.

Mass number

Total number of protons plus neutrons in the nucleus.

Isotope

Forms of an element with the same atomic number but different mass numbers.

Acidity

How acidic a water solution is, based on H+ vs. OH- amounts.

pH

Measure of acidity; below 7 acidic, 7 neutral, above 7 basic.

Chemical formula

Shorthand showing the number of each atom or ion in a compound.

Organic compound

Contains at least two carbon atoms combined with other elements.

Inorganic compound

Any compound that isn't organic.

Complex carbohydrates

Polymers of simple sugars (e.g., starch, cellulose).

Proteins

Polymers of amino acids.

Nucleic acids

Polymers of nucleotides (e.g., DNA, RNA).

Lipids

Fats and waxes; a macromolecule not made of monomers.

Cell

Fundamental structural and functional unit of life.

Gene

DNA sequence that codes for a specific protein.

Trait

Characteristic passed from parents to offspring.

Chromosome

DNA double helix wrapped around proteins; made of thousands of genes.

Physical change

Change with no change in chemical composition.

Chemical change (chemical reaction)

Change in the chemical composition of substances.

Nuclear change

Change in the nuclei of atoms.

Radioactive decay

Unstable nuclei emit particles or radiation.

Nuclear fission

Large nuclei split into lighter nuclei, releasing energy and neutrons.

Nuclear fusion

Two light nuclei form a heavier nucleus, releasing energy.

Law of conservation of matter

No atoms are created or destroyed in a physical or chemical change.

Energy

Capacity to do work or transfer heat.

Kinetic energy

Energy of motion.

Potential energy

Stored energy available for use.

Heat (thermal energy)

Total kinetic energy of all moving particles in a substance.

Electromagnetic radiation

Energy traveling as a wave of changing electric and magnetic fields.

Renewable energy

Replenished by natural processes in a relatively short time.

Nonrenewable energy

Can be depleted and isn't replenished on a human time scale.

Fossil fuels

Oil, coal, and natural gas, formed from decayed ancient organisms.

Energy quality

Capacity of a type of energy to do useful work.

High-quality energy

Concentrated energy with a high capacity to do work.

Low-quality energy

Dispersed energy with little capacity to do work.

Energy efficiency

Getting more work out of the energy we use.

System

Set of components that function and interact in some regular way.

Inputs

Matter, energy, and information entering a system.

Flows (throughputs)

Matter and energy moving within a system.

Outputs

Matter and energy leaving a system.

Feedback

Any process that increases or decreases a change to a system.

Feedback loop

An output is fed back into the system as an input.

Positive feedback loop

Pushes a system further in the same direction.

Negative (corrective) feedback loop

Pushes a system in the opposite direction.

Time delay

Lag between a feedback stimulus and the system's response.

Tipping point (threshold level)

Point where a fundamental shift in a system occurs.

Synergistic interaction (synergy)

Combined effect of processes greater than the sum of their separate effects.