Integrated Science & Periodic Table Atoms are the smallest particles used in order to identify an element. These elements are made up of only one specific kind of atom (Chang 2010). The difference between a mixture and a compound lies in the fundamentals of what makes up both substances. A compound is a substance that contains more than one element, but in fixed proportions, making it a molecule. No matter how large or small the amount of compound, the proportions will always have to be the same in order for the substance to qualify as a specific compound made up of the molecules (Chang 2010). For example, water is a molecule containing, one oxygen atom and two hydrogen atoms. The combination of these specific atoms in specific proportions is what makes it a compound. If the elements forming this compound were to be broken up, the compound itself would change therefore we would no longer have water. A mixture on the other hand is not dependent on proportions or compositions. It is the mixing of various elements or molecules, but changing the proportion of each will not change the overall mixture (Chang 2010). For example, milk is a mixture of fat, protein, and sugar. Adding water to this will not change the fact that it is milk -- it'll just be less pure.

If a pure substance were to be had, one can tell if it is indeed a compound or element by attempting to break it down even further. As previously stated, a compound is the combination of elements or molecules...

If a pure substance is not able to be broken down anymore, then it only contains one element. However, if the substance is able to be separated into more than one element, then it is considered to be a compound (Chang 2010).
There are two commonly known types of bonds: ionic and covalent. An ionic bond forms when ions come together to form a compound. Every atom contains a nucleus of neutrons (neutrally-charged particles) and protons (positively charged particles). Even though these particles are able to be separated, it takes an immense amount of energy to remove a proton or a neutron (Chang 2010). However, an atom also contains electrons, which are negatively charged particles. Because these particles are not directly part of the nucleus, but are instead orbiting the outside of the nucleus, they are able to be removed more swiftly. An ionic bond is the removal or addition of electrons when combing with other elements (Chang 2010). Removing a proton would change the element altogether, but adding an electron would make it more negatively charged (anion) or removing an electron would make it more positively charged (cation) (Chang 2010). An ionic bond is held together by the attractive forces that exist between the elements. While ionic bonds gain or lose electrons, a covalent bonds share them. The valence electrons that surround each element are shared among two or more elements (Chang 2010).

Ionic compounds are formed when a…