Quiz 3 Study Guide
6 Grade Science – Miss Fox
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*Refer to Text Book – Foldable and your Science Journal.
Radiation: transfer of energy through space, as electromagnetic waves like from the sun or from a light bulb.
 Electromagnetic energy (wave) is a form of energy that can travel through a vacuum.
 Vacuum: region where no matter (atoms or molecules) exists (empty space).
Conduction: The transfer of energy through a substance. In heat conduction, energy is transferred from
molecule to molecule by direct contact; the molecules vibrate against each other.
 Thermal Conduction is transferring heat through a material like when a metal spoon gets hot from
stirring hot soup. Near the surface of the earth, air is heated by thermal conduction.
 Conductor: substance that conducts heat easily. Heat is transferred through solids by conduction. A
conductor is a substance that allows heat to move through it easily. All metals are good conductors.
Convection is the transfer of thermal energy by the circulation or movement of a liquid or a gas (fluid). Boiling
water is an example of convection.
 Convection current: movement of gases or liquids caused by differences in density. Convection
Currents occur when warm air or water rises (becomes less dense) and cool air or water sinks (becomes
more dense).
The greenhouse effect: is the warming of the surface and lower atmosphere of the earth that occurs when
carbon dioxide (CO2), methane, nitrous oxide and other gases in the atmosphere absorb and trap and reradiate
thermal energy back to the earth.
Human activities significantly add to the level of greenhouse gases in the atmosphere.
Global warming: is the gradual increase in average global temperature. Many scientists believe that increasing
amounts of greenhouse gases (carbon dioxide, water vapor, and other gases in the atmosphere) may be
responsible for global warming.
Wind: is air that moves parallel to the ground.
How Wind Develops:
 Caused by a difference in air pressure due to unequal heating of the atmosphere.
 Heating the air, decreases pressure (warm air rises creating a low pressure)
 Cool air rushes into replace the warm air (cooler dense air, produces high pressure)
 As air goes from high to low pressure, winds form.
 Hot air rises because it is less dense, cold air sinks because it is denser. This causes convection currents
in the atmosphere.
Two Types of Winds: Local Winds & Global Winds.
Local Winds
 Cover short distances & blow from any direction
Types of Local Winds
 Sea Breezes, Land Breezes, Mountain Breezes & Valley Breezes.
 Land and sea breezes are caused by different temperatures over sea and land. During a summer day
in CT, the air is cooler over the Long Island Sound and warmer over land.
Global Winds
 Don’t travel North and South because of the Earth rotating on its axis.
Types of Global Winds
 Polar easterlies: prevailing winds that blow from east to west. In the Northern hemisphere the polar
easterlies can carry cold arctic air over the United States, producing rain and snow.
 Westerlies: prevailing winds that blow from west to in both hemispheres. The westerlies can carry
moist air over the United States, producing rain and snow.
 Trade winds: prevailing winds that blow northeast from 30 north latitude to the equator and that blow
southeast from 30 south latitude to the equator
 Doldrums: around the equator. Very little wind.
 Horse latitudes: located over the ocean, having high barometric pressure, and changeable winds.
 Jet stream: a narrow belt of strong winds that blow in the upper troposphere.
 Westerlies are the global winds which mainly affects the weather in Connecticut.
Coriolis effect: the apparent curving of the path of a moving object from an otherwise straight path due to
Earths rotation.
Prevailing winds: are winds that blow mainly from one direction during a given period.