Mass or volume-------------
There are following layers in earth atmosphere
a) Troposhere: the innermost layer or lowest part of atmosphere
b)stratosphere: next to troposhere
c)mesosphere:above stratosphere, here lowest temperature is observed
d)Thermosphere and Ionosphere: This layer allows long distance radio communication
e)Exosphere: this layer separates outer space from earth's surface.
<span>Glucose and oxygen react together in cells to produce carbon dioxide and water and releases energy.</span>
Answer: Carbon dioxide is a pure substance.
Explanation: A pure substance is defined when a substance has a single type of molecule. If more than 1 type of molecule is present in a substance, then it is considered as a mixture.
- Soda is basically a mixture of water and carbon dioxide. More than 1 type of molecule is present.
- Gasoline is a mixture of may gases. More than 1 type of molecule is present.
- Salt water contains salt and water molecules, hence it is considered as a mixture.
- Carbon dioxide has only 1 type of molecule which is
molecules. Hence, it is a pure substance.