Models of the Atom Timeline

Is an electrically neutral group of two or more atoms held together by covalent chemical bonds

This Chemistry lesson is titled Converting between Moles Atoms and Molecules Part 2 and will give a detailed explanation of the topic.

We'll learn how to determine the oxidation numbers or oxidation states for a the elements in a chemical compound. The oxidation numbers tell us how electrons are divided up or shared between atoms in a chemical compound. The oxidation numbers also tell us how electrons move in an oxidation reduction (redox) reaction. There are a set a rules that we use to determine oxidation number. Group 1A elements (alkalai metals) always have an oxidation of +1. Group 2A elements (alkaline earth metals) always have an oxidation number of +2. Elements on their own have an oxidation number of 0, and monatomic ions have an oxidation number that is equal to the ionic charge.

This lesson will look at an example to explain the size of an atom. This lesson will begin by looking at the structure of a tree and minimize it, with the measurements all the way down to molecules. This lesson will also touch on the invention of fluorescent microscopes to be able to view such small entities.

One in a series of videos looking at isomerism in organic chemistry. This one examines the five different chain structural isomers of C6H14, including a look at the 3-dimensional shapes of the molecules.