7th grade Science

atmosphere

Earth's air, which is made up of a thin layer of gases, solids, and liquids, forms a protective layer around the planet and is divided into five distinct layers.

chlorofluorocarbons

groups of chemical compounds used in refrigerators, air conditioners, foam packaging, and aerosol sprays that may enter the atmosphere and destroy ozone.

condensation

process in which water vapor changes to a liquid.

conduction

transfer of energy that occurs when molecules bump into each other.

convection

transfer of heat by the flow of material.

Coriolis effect

causes moving air and water to turn left in the southern hemisphere and turn right in the northern hemisphere due to Earth's rotation.

hydrosphere

all the water on Earth's surface.

ionosphere

layer of electrically charged particles in the thermosphere that absorbs AM radio waves during the day and reflects them back at night.

jet stream

narrow belt of strong winds that blows near the top of the troposphere.

land breeze

movement of air from land to sea at night, created when cooler, denser air from the land forces up warmer air over the sea.

ozone layer

layer of the stratosphere with a high concentration of ozone; absorbs most of the Sun's harmful ultraviolet radiation.

radiation

energy transferred by waves or rays.

sea breeze

movement of air from sea to land during the day when cooler air from above the water moves over land, forcing the heated, less dense air above the land to rise.

troposphere

layer of Earth's atmosphere that is closest to the ground, contains 99% of the water vapor and 75% of the atmospheric gases, and is where clouds and weather occur.

ultraviolet radiation

a type of energy that comes to Earth from the Sun, can damage skin and cause cancer, and is mostly absorbed by the ozone layer.