Browse Q&A by Concept
Select from the lists below to view frequently asked questions organized by concept.- Atoms and Molecules
- Earth's Shape
- Earth's Magnetic Field
- Earth's Rotations
- Earth's Revolutions
- Coriolis Effect
- Seasons
- Eclipses
- Solar Eclipses
- Lunar Eclipses
- Lunar Phases
- Earth's Interior
- Earth's Outer Layers
- Earth's Inner Layers
- Earth's Crust
- Earth's Mantle
- Earth's Core
- Lithosphere and Asthenosphere
- Minerals
- Mineral Groups
- Mineral Identification
- Mineral Formation
- Rocks
- Rock Cycle Processes
- Igneous Rocks
- Intrusive and Extrusive Igneous Rocks
- Igneous Rock Classification
- Sedimentary Rocks
- Lithification of Sedimentary Rocks
- Sedimentary Rock Classification
- Metamorphic Rocks
- Metamorphic Rock Classification
- Continental Drift
- Wegener and the Continental Drift Hypothesis
- Magnetic Polarity Evidence for Continental Drift
- Bathymetric Evidence for Seafloor Spreading
- Magnetic Evidence for Seafloor Spreading
- Seafloor Spreading Hypothesis
- Earth's Tectonic Plates
- Tectonic Plate Motions
- Theory of Plate Tectonics
- Divergent Plate Boundaries in the Oceans
- Divergent Plate Boundaries
- Transform Plate Boundaries
- Ocean-Continent Convergent Plate Boundaries
- Ocean-Ocean Convergent Plate Boundaries
- Continent-Continent Convergent Plate Boundaries
- Continental Margins
- Supercontinent Cycle and Pangaea
- Intraplate Activity
- Geological Stresses
- Principle of Horizontality
- Folds
- Faults
- Mountain Building
- Earthquakes
- Earthquake Zones
- Earthquakes at Transform Plate Boundaries
- Earthquakes at Convergent Plate Boundaries
- Intraplate Earthquakes
- Seismic Waves
- Tsunami
- 21st Century Tsunami
- Measuring Earthquake Magnitude
- Locating Earthquake Epicenters
- Earthquake Magnitude Scales
- Predicting Earthquakes
- Earthquake Damage
- Earthquake Safe Structures
- Staying Safe in an Earthquake
- Distribution of Water on Earth
- States of Water
- The Water Cycle
- Uses of Water
- Water Distribution
- Safety of Water
- Conserving Water
- Streams and Rivers
- Ponds and Lakes
- Flooding
- Glaciers
- Groundwater
- Groundwater Aquifers
- Springs and Geysers
- Groundwater Depletion
- Groundwater Pollution
- Water Pollution
- Protecting Water From Pollution
- Cleaning Up Groundwater
- Importance of the Atmosphere
- Composition of the Atmosphere
- Pressure and Density of the Atmosphere
- Temperature of the Atmosphere
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere and Beyond
- Electromagnetic Energy in the Atmosphere
- Solar Energy on Earth
- Heat Transfer in the Atmosphere
- Heat Budget of Planet Earth
- Solar Energy and Latitude
- Greenhouse Effect
- Circulation in the Atmosphere
- Local Winds
- Global Wind Belts
- Air Quality
- Types of Air Pollution
- Effects of Air Pollution on the Environment
- Causes Of Air Pollution
- Acid Rain
- Ozone Depletion
- Reducing Air Pollution
- Weather vs. Climate
- Effect of Latitude on Climate
- Effect of Atmospheric Circulation on Climate
- Effect of Continental Position on Climate
- Effect of Altitude and Mountains on Climate
- Climate Zones and Biomes
- Tropical Moist Climates
- Dry Climates
- Temperate Climates
- Continental Climates
- Polar Climates
- Climate Change in Earth History
- Short-Term Climate Change
- Carbon Cycle and Climate
- Global Warming
- Causes and Effects of Global Warming
- Impact of Continued Global Warming
- Reducing Greenhouse Gas Pollution
- How Fossilization Creates Fossils
- Types of Fossilization
- Earth History and Clues from Fossils
- Principles of Relative Dating
- Determining Relative Ages
- Correlation Using Relative Ages
- Geologic Time Scale
- Tree Rings, Ice Cores, and Varves
- Radioactive Decay as a Measure of Age
- Radiometric Dating
- Age of Earth
- Modern Biodiversity
- Characteristics and Origins of Life
- Metabolism and Replication
- Adaptation and Evolution of Populations
- Theory of Evolution by Natural Selection
- Population Size
- Extinction and Radiation of Life
- Growth of Human Populations
- Agriculture and Human Population Growth
- Revolutions in Human Population Growth
- Overpopulation and Over-Consumption
- Future Human Population Growth
- Sustainable Development