Yemi's Sigma Study Guide for Apes chapter 1 and 2.

Environment

All living and nonliving things around us, including air, water, energy, and organisms.

Environmental Science

The study of how humans interact with the environment and natural systems.

Environmentalism

A social movement aimed at protecting the environment through advocacy and action.

Natural disturbances

Events such as hurricanes, floods, wildfires that disrupt ecosystems.

Anthropogenic disturbances

Human-caused events such as deforestation, urbanization, pollution.

Ecosystem services

Benefits humans obtain from ecosystems (e.g., clean water, pollination, oxygen). When lost, ecosystem health and human survival decline.

Five environmental indicators

Biological diversity, food production, average global surface temperature and CO₂ concentration, human population, resource depletion.

Sustainability

Using resources without depleting them for future generations. Consider resource use, biodiversity, energy efficiency, and renewable alternatives.

Ecological footprint

The amount of land and water needed to sustain an individual's lifestyle. The U.S. footprint is among the largest compared to other nations.

Greenhouse effect

Trapping of heat in Earth's atmosphere by greenhouse gases (CO₂, CH₄, water vapor). Effects: climate change, melting ice, rising seas.

Scientific method steps

Ask a question → Hypothesis → Experiment → Collect data → Analyze → Conclusion.

Independent variable

The factor changed in an experiment

Dependent variable

The factor measured in an experiment.

Experimental group

The group that receives the treatment.

Control group

The group that does not receive the treatment; used for comparison.

Common concentration units

ppm (parts per million), ppb (parts per billion), ppt (parts per trillion). Useful for estimating pollutant toxicity.

Experimental group

The group that receives the treatment.

Control group

The group that does not receive the treatment; used for comparison.

Isotopes

Atoms of the same element with different numbers of neutrons.

Radioisotopes

Unstable isotopes that emit radiation. Uses: carbon dating, medical imaging, nuclear power.

Half-life

Time it takes for half the atoms in a radioactive substance to decay.

pH scale

Measures acidity/basicity (0 = acidic, 14 = basic, 7 = neutral). Logarithmic: each unit = 10× change in H⁺ concentration.

Acid rain

Caused by SO₂ and NOₓ reacting with water in the atmosphere, lowering pH of rainwater.

Energy - Capacity to do work.

Power

Rate of energy use (energy per unit time).

First law of thermodynamics

Energy cannot be created or destroyed, only transformed.

Second law of thermodynamics

Energy conversions increase entropy (disorder); energy is lost as heat.

Entropy

disorder in a system; always increases in energy transfers

Energy efficiency

ratio of useful energy output to energy input. Example: A car engine is 20% efficient.

Open system

Energy and matter can enter and leave. Example: coffee cup.

Closed system

self-contained system with little exchange of energy or matter. Example: coffee thermos.

Positive feedback loop

Increases change in a system; destabilizing. Example: melting ice → more warming.

Negative feedback loop

Reduces change; stabilizing. Example: predator-prey population control.

Steady State

inputs are equal to outputs so the ecosystem isn't changing over time.

Acids

contribute to H+ ions to solutions, based contribute OH- ions to solutions

Electromagnetic Spectrum

electromagnetic radiation takes many forms depending on wavelength(Ex: x-rays, infrared, radio, gamma)

Ionic bonds

involve a transfer of electrons (ex:salt).

Water

A universal solvent dissolving many substances on Earth.

Covalent Bonds.