Science 2-2

THE HYDROSPHERE

All the water on Earth. Almost all the water in the hydrosphere is salty. Only 3% is fresh water. Fresh water is found in streams, lakes, and rivers. It is also frozen in glaciers and the polar ice sheets and is found underground in soil and bedrock.

THE CARBON CYCLE

Almost all the chemicals that make up living things are based on carbon. Like nitrogen, carbon cycles through the Earth system.

How does energy enter the Earth system from internal sources (Why is the center of Earth so hot?)

Convection transfers heat from within Earth to Earth's surface. When rock in the mesosphere and asthenosphere gets warmer, it rises toward the surface. Cooler rock that is near the surface sinks. The rock moves in a circular pattern, like water in a pan on a stove.

THE NITROGEN CYCLE

Living things use nitrogen to build proteins and other important chemicals.

THE WATER CYCLE

Movement of water. Water is always moving between the atmosphere, land, oceans, and living things.

Explain how gravity can be considered an external energy source for Earth.

The pull of the sun and moon on the oceans helps create tides that cause currents and help ocean water mix.

THE PHOSPHORUS CYCLE

Unlike carbon and nitrogen, phosphorus generally does not exist as a gas. Therefore, it is not found in the atmosphere. Most of the phosphorus on Earth is stored in rocks.

What is convection and how is it an internal energy source for Earth

When rock in the mesosphere and asthenosphere gets warmer, it rises toward the surface. Cooler rock that is near the surface sinks. The rock moves in a circular pattern, like water in a pan on a stove.

Atmosphere

a mixture of gases that surrounds a planet, moon, or other celestial body

system

a set of particles or interacting components considered to be a distinct physical entity for the purpose of study

open system

a system that exchanges both matter and energy with the surroundings. The jar shown below is an open system.

closed system

a system that exchanges energy but not matter with the surroundings. The sealed jar in the figure below is an example of a closed system.

The biosphereis

all Earth's living things. Organic matter from dead organisms is also part of thebiosphere. Once this organic matter has decomposed, it becomes part of the other three spheres. The biosphere extends from within Earth's crust to a few kilometers above Earth's surface.

The geosphere

all the rock and soil on the continents and on the ocean floor. The geosphere also includes the solid and liquid rock and metal inside Earth. Some natural processes, such as volcanic eruptions, bring matter from Earth's interior to its surface. Other natural processes move surface matter into Earth's interior.

1st law of thermodynamics

also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system

Explain the role of energy in the carbon cycle

energy is a solid, liquid, and a gas

cycle

group of processes that move matter between reservoirs

Early Earth was constantly being bombarded by meteorites, comets, and asteroids. Was early Earth an open system or a closed system

open because comets and asteroids move freely

reservoir

place where matter or energy is stored, For example, the oceans, atmosphere, and living things

2nd law of thermodynamics

states that the entropy of any isolated system always increases.

THE ATMOSPHERE

the layer of gases that surrounds Earth. The air we breathe is part of the atmosphere. The atmosphere also protects Earth from much of the sun's harmful radiation. About 78% of Earth's atmosphere is nitrogen gas. About 21% is oxygen gas. The rest is made up of other gases, such as argon and carbon dioxide.

geosphere

the mostly solid, rocky part of the Earth; extends from the center of the core to the surface of the crust

Four important matter cycles on Earth

the nitrogen cycle, the carbon cycle, the phosphorus cycle, and the water cycle.

biosphere

the part of Earth where life exists; includes all the living organisms on Earth

hydrosphere

the portion of the Earth that is water

What are the 4 cycles we learned about in class

water, phosphorus, carbon, nitrogen