World of Chemistry

This video explains chemical bonds: ionic, covalent, and the hydrogen bond. We will discuss some of these topics in depth later on, but right now it is a nice complement for the topic of hydrogen bonds in your biology class.  Enjoy!

This simple animation explains the difference between an IONIC bond and a COVALENT bond.

Ionic bonds generally happen between a metal and a non-metal, while covalent bonds usually occur between two non-metals.

We have talked about the three common states of matter: solid, liquid and gas; and we also briefly discussed the existence of a fourth state, when a gas becomes plasma.  This video from the University of Maryland provides a brief explanation of Plasma, and its applications.

This video shows a very good animation of a neutralization reaction between Hydrochloric Acid and Sodium Hydroxide.

In the following video you can find a simulation of what happens when we dissolve salt (Sodium Chloride - NaCl) in water.

This is a good example of the interaction of a polar solvent with an ionic compound when a dissolution takes place.

The following video shows a very good animation of the different molecular geometries caused by the interaction (repulsion) of the electron pairs creating bonds inside molelcules.

NOTE: In the second half of the video, the presenter discusses what happens when there are "d" orbitals involved in the valence level; although this is NOT required for our class discussion, you may find it interesting to watch.

These links show a series of videos relating in more detail the different stages in the scientific knowledge of the atom and its structure.  They are worth watching:

• Structure of the Atom 1:  Earliest Models
• Structure of the Atom 2:  Smaller than the Smallest (Dalton, Thompson models)
• Structure of the Atom 3:  The Rutherford Model
• Structure of the Atom 4:  The Bohr Model
• Structure of the Atom 5:  Spectra
• Structure of the Atom 6:  The Wave Mechanical Model

Although the videos are old, and the sound quality is not the best, I think you will find them very informative and easy to understand :)

Here is the presentation we reviewed in class:

And the videos we reviewed as part of the presentation:

Este corto video explica la evolución de los modelos atómicos, desde Dalton al modelo atómico moderno.