Question | Answer |
Ionic Bonds | A compound made of two or more elements |
Covalent Bond | a type of bond formed between atoms when they share electrons; covalent bonds are strom and chemically stable |
Molecule | a neutral molecule formed when electrons are shared by atoms rather than being gained or lost |
Compound | a substance formed by chemical union of 2 or more elements or ingridents in difinite posistion by weight |
Chemial formula | a combination of symbol used to express the chemical composition of a substance |
Water | a drinkable liquid that runs through rules,oceans,and steams |
Polytomic Ion | all of which are made up of a group of positively or negitively charged covalently bonded atoms |
Isotope | atoms of the same element with different numbers of neutrons |
oxidation state | hte number of electrons an atom gains, or shares when bording with another atom |
Metal | alkall metals,alkalive earth metals |
lunar eclipse | the blocking of sunlight to the moon that occurs when earth is directly between the sun and the moon |
Solar eclipse | the blocking of sunlight to earth that occurs when the moon is between the sun and the earth |
Moon Phases | the differnt shapes of the moon as seen from earth |
Solstice | the two days of the year on which neither hemisphere is directley overhead of either 235 degree south or 235 degree north |
equinox | the two days of the year on which neither hemisphere is tilted toward or away from the sun |
Rotation | the spining motion of the planet about its axis |
revolution | the movement of an object around another object |
neap tide | A tide that occurs when the difference between high and low tide is least; the lowest level of high tide. |
spring tide | The exceptionally high and low tides that occur at the time of the new moon or the full moon when the sun, moon, and earth are approximately aligned |
solar system | a star with a group of heviley bodies that revolve around it |
Milkey Way | a broad band of life that stretches across the sky and it caused by the light of a very great number of faint stars |
Galaxy | milkey way galazy. one of billions of system of stars, gas,dust,that make up the universe |
Universe | All matter and energy, including the earth, the galaxies, and the contents of intergalactic space, regarded as a whole. |
nebula | a cloud of interstellar gas and dust. |
H-R Diagram | the graph showing the absolute magnitude plotted against the surface temperature for a group of stars. |
Luminosity | the brightness of a star in comparison with that of the sun: the luminosity of Sirius expressed as 23 indicates an intrinsic brightness 23 times as great as that of the sun. |
Tempeture | a measure of the warmth or coldness of an object or substance with reference to some standard value. The temperature of two systems is the same when the systems are in thermal equilibrium. |
Red Giant | a star in an intermediate stage of evolution, characterized by a large volume, low surface temperature, and reddish hue. |
White Drawf | is what stars like our Sun become after they have exhausted their nuclear fuel. Near the end of its nuclear burning stage, such a star expels most of its outer material, creating a planetary nebula. |
Main Sequences | narrow band in the Hertzsprung-Russell diagram in which 90 percent of all observed stars are plotted. |
Sun | the star that is the central body of the solar system, around which the planets revolve and from which they receive light and heat: its mean distance from the earth is about 93 million miles |
Focal Point | either of two points on the axis of a mirror, lens, or other optical system |
Refraction of light | is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. |
Reflection of light | is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated |
Water Cycle | the natural sequence through which water passes into the atmosphere as water vapor, precipitates to earth in liquid or solid form, and ultimately returns to the atmosphere through evaporation. |
Groundwater | the water beneath the surface of the ground, consisting largely of surface water that has seeped down: the source of water in springs and wells |
Irrigation | the artificial application of water to land to assist in the production of crops. |
Condensation | a reaction between two or more organic molecules leading to the formation of a larger molecule and the elimination of a simple molecule such as water or alcohol. |
Point Pollution | is a single identifiable localized source of air, water, thermal, noise or light pollution. |
Non-Point Pollution | to mean any source of water pollution that does not meet the legal definition of "point source" in section 502(14) of the Clean Water Act. That definition states: |
Wetlands | land that has a wet and spongy soil, as a marsh, swamp, or bog. |
Precipatation | falling products of condensation in the atmosphere, as rain, snow, or hail. |
Layers of atmosphere | The atmosphere of the Earth may be divided into several distinct layers, as the following figure indicates |
Troposphere | The lowest region of the atmosphere between the earth's surface and the tropopause, characterized by decreasing temperature with increasing altitude |
Stratosphere | the region of the upper atmosphere extending upward from the tropopause to about 30 miles (50 km) above the earth, characterized by little vertical change in temperature |
Mesosphere | the region between the ionosphere and the exosphere, extending from about 250–650 mi. (400–1050 km) above the surface of the earth |
Thermosphere | the region of the upper atmosphere in which temperature increases continuously with altitude, encompassing essentially all of the atmosphere above the mesosphere. |
Ionosphere | the region of the earth's atmosphere between the stratosphere and the exosphere, consisting of several ionized layers and extending from about 50 to 250 mi. (80 to 400 km) above the surface of the earth. |
Exosphere | the highest region of the atmosphere, where the air density is so low that a fast-moving air molecule is more than 50 percent likely to escape from the atmosphere instead of hitting other molecules |
Thunderstorm | a transient storm of lightning and thunder, usually with rain and gusty winds, sometimes with hail or snow, produced by cumulonimbus clouds. |
Tornado | a localized, violently destructive windstorm occurring over land, esp. in the Middle West, and characterized by a long, funnel-shaped cloud extending toward the ground and made visible by condensation and debris. Compare waterspout ( def. 3 ) |
Hurricane | a violent, tropical, cyclonic storm of the western North Atlantic, having wind speeds of or in excess of 72 mph (32 m/sec). Compare tropical cyclone, typhoon. |
Cumulonimbus clouds | Cumulonimbus clouds belong to the Clouds with Vertical Growth group. They are generally known as thunderstorm clouds. A cumulonimbus cloud can grow up to 10km high |
Nimbostratus clouds | Nimbostratus clouds belong to the Low Cloud (surface to 2000m up) group. They are dark gray with a ragged base. Nimbostratus clouds are associated with continuous rain or snow. Sometimes they cover the whole sky and you can't see the edges of the cloud |
Cold Front | the zone separating two air masses, of which the cooler, denser mass is advancing and replacing the warmer |
Warm Front | transition zone between a mass of warm air and the colder air it is replacing |
High Pressure system | A weather system associated with clear skies, and often cool, denser air |
Low Pressure System | An area of a relative pressure minimum that has converging winds and rotates in the same direction as the earth. This is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. |