We know this because of the discovery of fossils and bones. We can find out roughly when they existed because of carbon dating.
The Bohr Model, which was proposed by Niels Bohr in 1913
Answer:
Warm air rises, resulting in a decrease air pressure.
Explanation:
Tornado is the rapid and violent rotation of column of air which move from the thunderstorm to the ground.
It is formed when there is collision between warm and cold air. The cold air which is more sense than the warm air is pushed over the warm air which result in thunderstorms. The warm air then rises which result in decrease air pressure causing an updraft. The updraft then begin to rotate as there are variations in wind speeds and directions.
Answer:
Motion is defined as a change of position. How we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion.
Explanation:
- Answer: <em><u>The compounds containing CFCs (chlorofluorocarbons) are mainly responsible for ozone layer depletion as these compounds react with ozone in the presence of ultraviolet rays to form oxygen molecule and thus, destroying ozone.</u></em>
Explanation: <em><u>Human activities cause the emission of halogen source gases that contain chlorine and bromine atoms. These emissions into the atmosphere ultimately lead to stratospheric ozone depletion. The source gases that contain only carbon, chlorine, and fluorine are called chlo- rofluorocarbons usually abbreviated as CFCs.</u></em>
