Pure Substance VS. Mixture: A pure Substance CANNOT be separated by physical changes, but a Mixture can.
PURE SUBSTANCE: Element VS. Compound: An Element is one simple atom while a compound is two or more. Example: Al (Aluminum) is an Element. CaCl (Calcium Chloride) is a compound. You can split a compound with chemical changes because if you were to take the example, it would be a Calcium atom and a Chlorine atom. You CANNOT split a single atom (Element) unless you want to make an atomic bomb which takes a lot of energy and you don’t want to destroy the whole world.
MIXTURE: Homogeneous VS. Heterogeneous:
Homo- mixed; cannot differentiate pieces Hetero- can differentiate pieces EX: homo- ketchup (can you see the difference in the vinegar and tomato paste? No) Hetero- chicken noodle soup (there’s broth, chicken, peas, carrots, and other things)
The third beaker: since it has the most amount of salt and the same amount of water as all the other beakers . So it has the highest concentrated amount :)