Have scientist actually seen atoms?
NO
The scanning tunneling electron microscope "pictures" that you see are not pictures of atoms. Instead, they are the result of computer calculations involving electricity and a theory called quantum mechanics.
The moisture contents of air
Humidity
What gas makes up the largest percentage of the air we inhale?
Nitrogen
The number of molecules (or atoms) of a substance in a mixture for every 1 million molecules (or atoms) in that mixture
Parts per million
Using 1m = 100 cm convert 1.3 meters to centimeters
130 cm
The smallest chemical unit of matter
Atom
The mass of water vapor contained in a certain volume of air
Absolute humidity
Approximately what percentage of dry air is oxygen?
21%
Which layer of the atosphere helps sheild living things from harmful UV radiation?
Ozone layer
Using 1 kg= 1,000 g, convert 75 kilograms to grams
75,000 g
Two or more atoms linked together to make a substance with unique properties
Molecule
The ratio of the mass of water vapor in the air at a given temperature to the maximum mass of water vapor the air could hold at that temperature, expressed as a percentage
Relative humidity
What gas makes up the majority of the air we exhale?
Nitrogen
Is ozone considered helpful of harmful when it is found near Earth's surface?
Harmful
it is an air pollutant
Using 1 gallon= 3.78 liters, convert 0.500 gallons to liters
1.89 L
The quantity of a substance within a certain volume
Concentration
Does water vapor evaporate more slowly when relative humidity is high of low?
High humidity
What would happen if all carbon dioxide were removed form Earth's atmosphere?
the earth would be colder
plants could not preform photosynthesis
What device in automobiles helps reduce harmful pollutants in exhaust?
Catalytic converter
Using 1 in.= 2.54 cm, convert 100 centimeters to inches
39.4 in
Carbon disulfide can be broken down into sulfur and carbon. Is carbon disulfide made of atoms of molecules?
Molecules
Why does sweating cool your body?
Sweat evaporates, taking heat away from the body
The process by which certain gases trap heat that radiates from the earth
Greenhouse effect
What pollutant concentration decreases significantly after catalytic converters were required in automobiles?
Carbon monoxide
Using 1%= 10,000 ppm, convert 0.023% nitrogen oxides to parts per million
230 ppm