ESS regents study questions

What observational evidence shows that the universe is currently expanding?

The redshift of light from almost all distant galaxies.

How does redshift indicate that a galaxy is moving away from Earth?

Light wavelengths are stretched toward the longer, red end of the spectrum.

What is cosmic microwave background (CMB) radiation?

Faint, uniform electromagnetic radiation remaining from the early stages of the Big Bang.

How does CMB radiation support the Big Bang Theory?

It represents the leftover, cooled thermal energy from the early hot universe.

What are the two primary elements formed during the Big Bang?

Hydrogen and helium.

By what process do stars generate light and heat energy?

Nuclear fusion in their cores.

What occurs during nuclear fusion in a main sequence star?

Hydrogen nuclei fuse under high pressure and temperature to form helium.

Where are elements heavier than iron formed?

In supernova explosions of high-mass stars.

What is stellar nucleosynthesis?

The process of forming chemical elements inside stars through nuclear fusion.

Which force governs the orbital motion of planets and galaxies?

Gravity.

What two factors determine the strength of the gravitational force between objects?

The masses of the objects and the distance between them.

How old is the universe estimated to be?

Approximately 13.8 billion years old.

How old is Earth and the solar system?

Approximately 4.6 billion years old.

What is a light-year?

The distance that light travels in one year, about 9.5 trillion kilometers.

Why is the heavy cratering on the Moon not visible on Earth?

Earth's active weathering, erosion, and plate tectonics have erased most craters.

What does heavy cratering on planetary bodies indicate about the early solar system?

The early solar system was a violent environment filled with debris.

What was the composition of Earth's early atmosphere?

Volcanic gases like carbon dioxide, water vapor, and nitrogen, with no free oxygen.

How did Earth's early atmosphere form?

Through volcanic outgassing during the planet's early molten stage.

What process allows scientists to determine the absolute age of rock layers?

Radiometric dating of radioactive isotopes.

What is a half-life?

The time required for half of a radioactive parent isotope to decay.

How does the rate of radioactive decay change over time?

It remains constant and is unaffected by external environmental conditions.

Why is Carbon-14 used to date recent organic remains rather than ancient rocks?

Its short half-life of 5,730 years makes it decay too quickly for old rocks.

Which isotope is best suited for dating the oldest rocks on Earth?

Uranium-238, due to its half-life of 4.5 billion years.

How is the Geologic Time Scale divided?

Into units based on major fossil record events, like mass extinctions.

What percentage of Earth's history is represented by the Precambrian eon?

About 88 percent of Earth's history.

What evidence supports the theory that continents were once joined?

Matching fossils, rock types, and mountain belts across ocean basins.

How does magnetic striping on the ocean floor support plate tectonics?

It records reversals in Earth's magnetic field as new crust spreads outward.

What are the main characteristics of continental crust?

Thick, low density, and composed primarily of granitic rock.

What are the main characteristics of oceanic crust?

Thin, high density, and composed primarily of basaltic rock.

Why is oceanic crust generally much younger than continental crust?

Oceanic crust is continuously recycled back into the mantle at subduction zones.

What is the geosphere?

The solid portion of Earth, including the crust, mantle, and core.

What is the hydrosphere?

All of Earth's liquid water, including oceans, lakes, and groundwater.

What is the atmosphere?

The envelope of gases surrounding Earth, held in place by gravity.

What is the biosphere?

All living organisms and ecosystems on Earth.

What is the cryosphere?

The frozen water part of the Earth system, including glaciers and ice caps.

How do plants (biosphere) interact with the geosphere to form soil?

Plant roots break rocks physically, and organic acids decompose minerals chemically.

What is a positive feedback loop?

A system response that amplifies or accelerates the initial change.

What is a negative feedback loop?

A system response that counteracts or stabilizes the initial change.

What is dynamic equilibrium?

A state of balance achieved when opposing processes occur at equal rates.

What is thermal convection in Earth's mantle?

The rising of hot, less-dense rock and sinking of cooler, denser rock.

What is the primary driving engine of plate tectonic motion?

Mantle convection currents.

What is the lithosphere?

The rigid outer layer of Earth, consisting of the crust and upper mantle.

What is the asthenosphere?

The partially melted, plastic-like layer of the mantle directly below the lithosphere.

What occurs at a divergent plate boundary?

Tectonic plates pull apart from each other.

What seafloor feature is formed at divergent plate boundaries?

Mid-ocean ridges where new crust is created.

What occurs at a convergent plate boundary?

Tectonic plates collide or slide beneath one another.

What occurs during subduction?

A denser oceanic plate sinks beneath a less dense plate into the mantle.

What features form on the surface above an oceanic-continental subduction zone?

A deep ocean trench and a continental volcanic arc.

What surface feature forms when two continental plates collide?

High, folded mountain ranges, such as the Himalayas.

What occurs at a transform plate boundary?

Tectonic plates slide horizontally past one another.

How do volcanic eruptions in the geosphere affect the atmosphere?

They release large volumes of carbon dioxide and ash into the air.

What is physical weathering?

The mechanical breakdown of rock into smaller pieces without chemical alteration.

How does frost wedging break apart rock?

Water enters cracks, freezes, expands by nine percent, and wedges rock apart.

What is chemical weathering?

The decomposition of rock minerals through chemical reactions.

Under what climatic conditions does chemical weathering occur fastest?

Warm and wet climates.

How does acid rain cause chemical weathering of limestone?

It dissolves the mineral calcite, creating caves and sinkholes.

What is the difference between weathering and erosion?

Weathering breaks down rock; erosion transports the weathered sediments.

What is deposition?

The process where transported sediments are dropped or settled.

What force is the primary driver of erosion and mass wasting?

Gravity.

What is infiltration?

The process of water seeping into the ground through soil and rock.

What is runoff?

Water that flows over the land surface rather than soaking into the ground.

How does urbanization affect runoff and infiltration?

Pavement increases surface runoff and decreases ground infiltration.

What is porosity?

The percentage of open pore space in a rock or sediment.

What is permeability?

The ability of a material to allow water to pass through its pores.

Why is clay highly porous but impermeable?

Its pore spaces are extremely small and not well interconnected.

What source of energy drives evaporation in the water cycle?

Solar radiation from the Sun.

What is transpiration?

The release of water vapor into the atmosphere from plant leaves.

How does water velocity affect stream transport?

Faster water can carry larger sediment sizes.

How does a stream deposit sediments when it slows down?

It deposits the largest, densest particles first, sorting them by size.

What is a carbon reservoir?

A place where carbon is stored in the Earth system.

What is the largest carbon reservoir on Earth?

The lithosphere, stored in sedimentary rocks like limestone.

What is a carbon flux?

The rate at which carbon transfers between different reservoirs.

How does photosynthesis act as a carbon flux?

It moves carbon dioxide from the atmosphere into the biosphere.

How does respiration act as a carbon flux?

It releases carbon dioxide from the biosphere back into the atmosphere.

How has human activity disrupted the carbon cycle?

By burning fossil fuels, releasing ancient stored carbon into the atmosphere.

How does deforestation affect atmospheric carbon dioxide levels?

It reduces photosynthesis, leaving more carbon dioxide in the atmosphere.

What are greenhouse gases?

Gases that absorb and re-emit infrared radiation, trapping heat.

Name two major greenhouse gases.

Carbon dioxide and methane.

What is the relationship between atmospheric carbon dioxide and global temperature?

As carbon dioxide levels rise, global temperatures increase.

What is Earth's energy balance?

The balance between incoming short-wave solar radiation and outgoing long-wave infrared radiation.

How do greenhouse gases cause warming in terms of energy balance?

They absorb and trap outgoing long-wave infrared radiation.

What is albedo?

The measure of how reflective a surface is to solar radiation.

Which surface has a higher albedo: fresh snow or dark soil?

Fresh snow, because it reflects most incoming sunlight.

Describe the ice-albedo positive feedback loop.

Melting ice lowers albedo, absorbing more heat, which melts more ice.

Describe the water vapor feedback loop.

Warming causes more evaporation, increasing water vapor, which traps more heat.

What are climate models?

Mathematical representations used to simulate and project Earth's climate.

How do scientists validate climate models?

By testing them against known historical climate data.

What is radiation in heat transfer?

Energy transfer through space in the form of electromagnetic waves.

What is conduction in heat transfer?

The transfer of heat through direct physical contact between substances.

What is convection in heat transfer?

The transfer of heat by the circulation or movement of a fluid.

What is insolation?

Incoming solar radiation that reaches the Earth's surface.

Why does the equator receive more intense insolation than the poles?

The Sun's rays strike the equator at a more direct angle.

What is an air mass?

A large body of air with uniform temperature and humidity.

What characteristics define a maritime tropical (mT) air mass?

Warm and humid.

What characteristics define a continental polar (cP) air mass?

Cold and dry.

What is a weather front?

The boundary layer between two different air masses.

What is the Coriolis effect?

The deflection of moving air and water caused by Earth's rotation.

In which direction does the Coriolis effect deflect winds in the Northern Hemisphere?

To the right of their path of motion.

What weather conditions are associated with a low-pressure system?

Rising air, clouds, and precipitation.

What weather conditions are associated with a high-pressure system?

Sinking air, clear skies, and stable dry weather.