Answer:
Pure Substance. A sample of matter, either a single element or a single compound, that has definite chemical and physical properties. Element. A pure substance that cannot be broken down into other substances by chemical or physical means.
Explanation:
Sorry if it's wrong!!!!!!!
Answer:
This effect is caused by increased levels of carbon dioxide, chlorofluorocarbons and other gases in the air, many of them released by human activity. greenhouse effect The warming of Earth's atmosphere due to the buildup of heat-trapping gases, such as carbon dioxide and methane.
Explanation:
Percentage recovery gives us an idea of the amount of pure substance recovered after the chemical reaction. Percentage recovery can be more than 100 % or less than 100 %. Usually, in any experiment performed the weight percentage recovery will be less than 100. Percent recovery values greater than 100 show that the recovered compound is contaminated.
Amount of acetaminophen initially taken = 350 mg
Amount of acetaminophen obtained after recovery =185 mg
= 
= 52.9%
Answer:
This tells us the radial velocity of the object and that the object is approaching or coming towards us.
Explanation:
Certain chemicals radiate with particular wavelengths or colors when their temperature is raised or when they are charged electrically. Also observable are dark strokes separating the spectrum known as absorption lines
These spectral lines of chemicals are well known as stated above and from the phenomenon of Doppler effect, spectroscopy can be used to detect the movement of a distant object by the change of the emitted frequency of the wavelength
The Doppler effect is used in calculating the radial velocity of a distant object due to the fact that an approaching object compresses its emitted signal wavelength while a receding object has a longer wavelength than normal
