Geosphere
What are the three main layers of Earth's geosphere?
What are the crust, mantle, and core?
What percentage of Earth's total water is freshwater?
What is approximately 3%?
What two gases make up approximately 99% of Earth's atmosphere?
What are nitrogen (78%) and oxygen (21%)?
What is a scientific model?
A representation that describes, explains, or shows part of the natural world.
What is the biosphere?
All living organisms on Earth and the environments in which they live.
When rock inside Earth heats up, it becomes less dense and moves in which direction?
What is upward?
What are the four main changes of state of water?
Evaporation: Liquid to gas.
Condensation: Gas to liquid.
Freezing: Liquid to solid.
Melting: Solid to liquid.
What happens to air density as altitude increases?
Air density decreases as altitude increases.
What type of model uses equations to represent relationships?
What is a mathematical model?
How does matter move from one organism to another in the biosphere?
Through food chains, when organisms consume other organisms.
What is the difference between conduction and convection?
Why is ocean water salty, and how does evaporation contribute to its saltiness?
Weathering breaks down rocks and releases minerals. Rivers carry dissolved minerals into the ocean, and underwater volcanic activity and hydrothermal vents release additional minerals. When ocean water evaporates, the water becomes vapor while most dissolved salts remain behind, allowing salt to accumulate over billions of years.
Why does warm air rise and cooler air sink?
Warm air expands and becomes less dense, causing it to rise. Cooler air is denser, so gravity pulls it downward.
What type of model uses a familiar system to explain a more complicated system? Give an example.
What is an analogue model? An example is using flowing water to represent electric current.
Why is energy lost as heat at every level of a food chain?
Organisms use energy for cellular respiration, movement, growth, and maintaining body temperature. During these processes, some energy is released as heat into the surrounding environment. Energy transfers are not 100% efficient.
Explain the complete process of a convection cell inside Earth's mantle.
Rock in the mantle absorbs thermal energy from deeper inside Earth. The heated rock becomes less dense and rises. As it moves upward, it transfers energy to surrounding rock and eventually cools. The cooler rock becomes denser and sinks because of gravity. This cycle repeats.
Explain how differences in temperature and density create deep ocean currents.
The Sun heats ocean water, especially near the equator. Warm water becomes less dense and generally stays near the surface. Colder water becomes denser and sinks toward the ocean floor. This sinking and movement of water helps create deep ocean currents that circulate water around the planet.
What is the troposphere, and why is it important?
The troposphere is the lowest layer of Earth's atmosphere. It is important because most weather occurs there.
Why do scientists use models to study Earth's systems, and what is one limitation of models?
Scientists use models to visualize processes, explain concepts, represent things that are difficult to observe, and test predictions. A limitation is that models do not show every detail of reality and may leave out important parts of a real system.
What happened to oxygen levels inside Biosphere 2, and what caused the decline?
Oxygen levels decreased from 21% to 14.2%. Bacteria decomposed organic matter and used oxygen from the atmosphere during cellular respiration.
How does energy from Earth's interior cause volcanic activity? Include what matter the energy travels through and where the energy goes.
Thermal energy from Earth's interior transfers through solid mantle rock by conduction and through moving mantle material by convection. This energy heats surrounding rock and can contribute to melting, producing magma. Because magma is generally less dense than the surrounding rock, it can rise through cracks and volcanic vents toward Earth's surface, where it may erupt.
Describe how the Sun transfers energy to Earth's water and how that energy moves through the water cycle and ocean circulation. Identify the matter involved and where the energy goes.
The Sun transfers energy to Earth through radiation, traveling through space without needing matter. When sunlight reaches Earth's surface, oceans absorb that energy, warming liquid water. Some of this water evaporates, transferring energy into water vapor in the atmosphere. The vapor later condenses into liquid droplets, releasing energy into the surrounding atmosphere. The Sun also heats ocean water unevenly, creating temperature and density differences that help drive ocean currents. These currents redistribute heat through moving ocean water.
Explain how the Sun creates convection cells in the atmosphere and how they contribute to weather. Include what matter receives the energy and where the energy moves.
The Sun transfers energy through radiation to Earth's surface. Land and oceans absorb the energy and transfer heat to the air through conduction. The warmed air becomes less dense and rises, carrying thermal energy upward through the atmosphere. As the air rises, it cools and becomes denser, eventually sinking. This repeating movement of air creates convection cells that help drive winds, atmospheric circulation, and weather patterns.
What is the difference between a physical model and a computer model?
A physical model is a tangible object that scientists can observe or manipulate, such as a globe. A computer model is a computer-based simulation or representation of data.
What did scientists learn from Biosphere 2 about energy and matter cycling in a closed ecosystem?
Scientists learned that ecosystems are complex systems in which living organisms and nonliving components depend on one another. Even when an ecosystem is designed to support life, changes in one part can affect the entire system. For example, bacteria decomposing organic matter used oxygen, causing oxygen levels to decrease and making it difficult for humans to live inside the environment.