click below
click below
Normal Size Small Size show me how
8th Science
Chapter 7 CC 1
| Question | Answer |
|---|---|
| Atmosphere | The blanket of gases that surrounds our planet to protect and support life |
| The atmosphere can be broadly divided into two regions based on chemical composition: the ___ and ___ ___. | lower, upper, atmosphere |
| Homosphere (homo- means "same" or "uniform") | The lower atmosphere |
| Nitrogen | The most abundant gas that we breathe |
| Name the top four most abundant gases. | 1. nitrogen 2. oxygen 3. argon 4. carbon dioxide |
| Water vapor (can compose up to 4% of the air, depending on the air's humidity and altitude) | The gaseous form of water |
| Ozone | A relatively scarce type of oxygen molecule in which three oxygen atoms are bonded together that is within the upper limits of the atmosphere |
| Oxygen is ___ to humans and to most animal life. | vital |
| Carbon dioxide is vital for ___. | plants |
| Carbon dioxide and water vapor help give the earth a(n) ___ and ___ ___. | mild, stable, climate |
| Ozone helps the earth's surface by doing what? | It helps protect it from the sun's intense ultraviolet radiation |
| Turbopause | Lies at the end of the homosphere, it is the boundary or transitional zone between the lower and upper atmospheres |
| Heterosphere (hetro- means "different") | The upper atmosphere is called this because of its distinct layers |
| Trophosphere | The lowest layer of the atmosphere |
| The troposphere is the "__ __." | weather layer |
| Temperature gradient | A steady change in temperature as altitude increases |
| Tropopause | The point that marks the upper boundary of the troposphere |
| Stratosphere | The layer immediately above the tropopause |
| The stratosphere has strong, steady ___, but few ___ ___ ___. | winds, changes of weather |
| The ___ has a temperature gradient opposite that of the ___. | stratosphere, troposphere |
| The stratospheres upper boundary | Stratopause |
| ozone layer | Acts as a "shield" to protect the earth's surface from the dangerous effects of the sun's ultraviolet (UV) radiation |
| UVB | Causes tanning and sunburn |
| UVC | The most powerful and dangerous form of UV radiation; but it is completely absorbed in the ozone layer |
| Mesosphere (meso- means "middle" or "between") | The least-understood layer of the earth because it is to high for airplanes and to low for sattelites |
| Mesopause | The mesosphere's upper boundary; the coldest point in the atmosphere |
| Thermosphere (thermo- means "heat") | The layer immediately above the mesopause that is characterized by high temperatures |
| Thermopause | The upper boundary of the thermosphere |
| Vacuum | A space that does not contain any matter |
| Exosphere | The outermost layer of the atmosphere |
| Cosmic rays | The extremely powerful radiation that comes from deep space |
| Plasma | A special state of matter made up of a mixture of electrons and positive ions |
| Ionosphere | A portion of the earth composed of plasma air |
| The ionosphere acts like a giant ___, "bouncing" certain types of radio waves back down toward the ground. | mirror |
| An invisible force | magnetism |
| Magnetism is concentrated at two points known as ___. | poles |
| Imaginary lines used to map out a magnetic field's location and strength | Lines of force |
| Magnetic field | The region in which the magnet affects other objects |
| Solar wind | The stream of harmful, charged particles sent out by the sun |
| Magnetosphere | The region of the earth's magnetic field that is influenced by the solar wind |
| Magnetopause | The region (or boundary) where the solar wind meets with and presses on the magnetosphere |
| Megnetotail | The region of the magnetosphere that look like a tail |
| Auroras (also known as the northern and southern lights) | Are created when particles react with the atmosphere's molecules |
| Auroras that occur in the northern latitudes are called what? | Aurora borealis |
| Auroras that occur in the southern latitudes are called what? | Aurora australis |
| UVA | The least-harmful form of UV radiation |
| Van Allen radiation belts | Particles that are trapped in the magnetosphere are found in two different regions that look similar to belts or doughnuts encircling the earth's equator; these regions are known as this. |
| Atmospheric pressure | The force per square foot at sea level |
| The atmospheric pressure is normally equal to ___ pounds per square inch at sea level. | 14.7 |
| As altitude ___, air pressure ___. | increases, decreases |