Chemistry Terms

Elements and Compounds- They are both classified as substances and are found in mixtures. They are different because elements cannot be broken down any further and also because compounds are made of two or more substances while elements consist of only one.

Mixtures and compounds- They are both made of two or more substances, and also they both can be broken down further. This is also a difference because compounds can only be separated by chemical reactions. Another difference is that a compound has a fixed composition and is uniform throughout and a mixture is not.

Evaporation and boiling- They are alike because they both start with a liquid and end with a gas. Also, they bath involve a phase change. They are different because evaporation can happen at any temperature and boiling only happens when the temperature of the liquid is at or above its boiling point. Thy are also different because evaporation only happens at the surface and boiling occurs throughout the liquid.

Atomic models of Thompson and Bohr- The models are alike in the fact that both were thought to be a sphere. Also, they are alike because both models contained positively and negatively charged particles. One way that they are different is that Thompson believed that the particles were evenly spaced throughout the atom, while bohr said that the positive particles were in a nucleus and the negative particles orbited the nucleus. Another way that they are different is that Thompson thought the atom was solid while bohr stated that there was a lot of empty space throughout which the electrons moved.

Cations and Anions- One way that they are alike is that they are both ions. Another way that they are similar is that they are both attracted to oppositely charged ions. One way that they are different is that their charges are different. A cation has a positive charge while an anion has a negative charge. Another way that they are different is that most metals are cations while most non-metals are anions.

Atomic Models of Rutherford and Bohr- Before Bohr, the classical model of the atom was similar to the Copernican model of the solar system, where, just as the planets orbit the Sun, electrically-negative electrons