Earth Science: Our Earth

land

The word ‘Earth’ is Old English word for ___

Oblate Spheroid ( refers to its slightly oblong appearance.)

The true shape of the Earth is called an ___.

True

(True/False) Earth system is essentially a closed system. It receives energy from the sun and sends back some of this energy to space.

True

(True/False) Earth is a system composed of subsystems.

True

(True/False) A closed system is a system in which there is only an exchange of energy but no exchange of
matter.

ATMOSPHERE, HYDROSPHERE, LITHOSPHERE, BIOSPHERE

The four Earth subsystems

ATMOSPHERE

The totality of gases surrounding the planet.

78% nitrogen and 21% oxygen

The present atmosphere is composed of ___% nitrogen (N), ___ % oxygen (O2), 1% argon.

Thermosphere

The layer of the atmosphere where Aurora borealis can be found.

Stratosphere

The layer of the atmosphere where the ozone layer can be found.

Exosphere

The outermost layer of the atmosphere.

Mesosphere

The layer of the atmosphere where Meteors can be found burning up.

Troposphere

The layer of the atmosphere where airplanes fly at.

HYDROSPHERE

The totality of water; the subsystem that features all the various types of water

True

(True/False) Of all the water that exists on our planet, roughly 97% is saltwater and less than 3% is freshwater.

GEOSPHERE/LITHOSPHERE

The subsytem that is land where rocks and minerals are found.

BIOSPHERE

It includes all life on earth; On the surface. On water, air, or land.

CRUST, MANTLE, CORE

The three layers that make up the Earth’s internal structure.

Continental Crust

Found under land masses; Mainly made up of Silicon, Oxygen, Aluminum, Calcium, Sodium, and Potassium.

Oceanic Crust

Found under the ocean floor; Made of dense rocks

MANTLE

Found under the crust and the thickest internal structure that measures up to 2900 kilometers from the earth surface.

INNER CORE

Its temperature reaches 5000 degrees Celsius. It was solidified as a result of pressure freezing.

OUTER CORE

Its temperature reaches 2000 degrees Celsius and was melted.

iron and nickel

The core is made almost entirely of metal—specifically, ___