Early theories and observations by Dalton, Thompson, Millikan, and Rutherford shaped the way we view the modern structure of the atom.
2.3 The Modern View of Atomic Structure Part 1
2.3 The Modern View of Atomic Structure Part 2
What differentiates one atom from another is the number of protons it possesses. When the number of protons are varied, the identity of the atom is changed. Atoms are neutral species, meaning that they have the same number of protons and electrons. When the number of electrons is varied atoms form charged particles called ions. An ion with a positive charge is called a cation and an ion with a negative charge is an anion.
In addition to having varying number of electrons, atoms of a given element can also contain a varying number of neutrons, called isotopes. Since isotopes of an atom have different numbers of neutrons their mass is different.
2.4 Isotopes and Relative Atomic Mass Part 1
2.4 Isotopes and Relative Atomic Mass Part 2
Since atoms/ions/isotopes are extremely small, we need to come up with a unit of measure that is practical when describing their properties. The mole is defined as 6.022 x 1023 of something.
3.4 Avagadro’s Constant and the Mole
Most of the matter we will analyze and observe does not exist as single atoms. More commonly, matter exists as molecules or ions.
2.6 Molecules and Molecular Compounds
2.7 Ions and Ionic Compounds
Once we start to observe molecular and ionic compounds we need to come up with a system to name them. The system outlined in the videos below are the foundation of the vocabulary we use in chemistry and a knowledge of nomenclature is essential if you want to communicate with other chemists.
2.8 Nomenclature Part 1
2.8 Nomenclature Part 2
2.8 Nomenclature Part 3
2.8 Nomenclature Part 4