Environmental Science - Chapter 2

Terminology and Key Concepts

scientific methods

advance knowledge and understanding of how the natural world works

scientific hypothesis

a testable explanation of the data they collected.

scientific theory

A well-tested and widely accepted scientific hypothesis or a group of related hypotheses

Reliable science

the concepts and ideas that are widely accepted by experts in a particular field of the natural or social sciences

tentative science

results that have not undergone adequate testing and peer review

protons

positive charge

neutrons

no charge

electrons

negative charge

isotopes

Atoms of the same element that have different numbers of neutrons

atomic number

number of protons

organic compounds

carbon-based molecules

cell theory

idea that all living things are composed of cells

physical change

A change in a substance that does not involve a change in the identity of the substance

law of conservation of matter

Matter is not created nor destroyed in any chemical or physical change

kinetic energy

energy of motion

electromagnetic radiation

a form of energy that exhibits wavelike behavior as it travels through space

potential energy

stored energy

Energy quality

a measure of the capacity of energy to do useful work

High-quality energy

concentrated energy that has a high capacity to do useful work

energy released when we burn wood or concentrated sunlight

first law of thermodynamics

Energy cannot be created or destroyed

second law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

positive feedback loop

a feedback loop in which change in a system is amplified

model

an approximate physical or mathematical representation that is used to understand or explain the behavior of complex natural systems

scientific law or law of nature

a well-tested and widely accepted description of observations of what we find always happening in the same way in nature

matter

anything that has mass and takes up space

compounds

combinations of two or more different elements held together in fixed proportions.

pH

measure of acidity

organic compound

contain at least two carbon atoms combined with atoms of one or more other elements.

low quality energy

so dispersed that it has little capacity to do useful work

number of moving molecules in ocean or atmosphere

negative feedback loop

causes a system to change in the opposite direction

if a house is too cold a thermostat will turn heating on to get back to desired temperature