All mixtures contain only one kind of atom.
~Mschmindy
Democritus *suggested* the existence of the atom, that everything was made up of tiny particles, but wasn't really able to get more specific than that. Dalton also theorized that everything was made up of indivisible particles, but went further basing his theory on actual scientific principles, such as the Law of Conservation of Mass and the Law of Constant Composition. He also said that atoms weren't created or destroyed in a chemical reaction, just rearranged. There's more to it than that, but basically, Dalton's theory was based more on science while Democritus' theory was too general to be useful in chemical situations.
Solids and liquids have volumes thatdo not change easily. A gas, on the other hand, has a vol- ume thatchanges to match the volume of its container. The molecules in a gas are very far apart compared with the molecules in a solid or a liquid. The amount of space between the molecules in a gas can change easily.
Answer:
20 mL
Explanation:
<em>The student should record 20 mL as the correct volume.</em>
The curved surface of a liquid that is usually observed in a buret is referred to as the meniscus. This meniscus is created as a result of the surface tension of the liquid against the walls of the buret. <u>Hence, in order to avoid errors due to parallax, the bottom of the meniscus should be read and not the top.</u>
Therefore, the correct volume that the student should record is 20 mL.
