<span>Concentration of a chemical in a solution refers to how many of the chemical's molecules are sitting in a small volume of the solution. Concentration could be measured in molecules per liter, although molecules are so small compared to a liter that we usually use different units (just like we wouldn't want to measure the distance between the earth and the sun in inches). A gradient is a measurement of how much something changes as you move from one region to another. So a concentration gradient is a measurement of how the concentration of something changes from one place to another.
If this doesn't help here's a Khan Academy video </span><span>https://www.khanacademy.org/...and.../concentration-gradients</span>
True because its still technically the same substance
Answer:
Crude oil is a mixture of comparatively volatile liquid hydrocarbons (compounds composed mainly of hydrogen and carbon), though it also contains some nitrogen, sulfur, and oxygen. Those elements form a large variety of complex molecular structures, some of which cannot be readily identified.
Condensation because the water vapor has a high entropy(disorder) and liquid water has a lower entropy.
