What is an element? (Periodic Tables on the Web)
You can tell a lot about a fellow's character by his way of eating jelly beans.
- - -Ronald Reagan (from "Brain Candy Celebrity Quotes". http://www.corsinet.com/braincandy/advise.html. Accessed 7/18/08)
There are hundreds of periodic tables on the web. Get to know your element by looking at these periodic table sites.
- Periodic Table of Comic Books - index to elements in comic books
- Carondelet High School Periodic Table - created by Carondelet High School students
- Lenntech Periodic Table - good for health and environmental effects
- WebElements - Lots of information about elements and element compounds, including history, uses, abundance on earth and in living organisms
- Elementymology and Elements Multidictionary - Find the name of your element in different languages:
Complete Question 2 of your Lab Report. While you wait for others to finish this part, try one of these periodic table games:
- Find the element (Royal Society of Chemistry)
- Periodic Table Quiz
Share information about your element with the group.
Can we see elements and molecules?
Let's start by looking at the crystal structure of your element using a Java applet called Jmol.
- Find your element again at WebElements.
- Click on CRYSTAL STRUCTURE (right margin).
- Click on INTERACTIVELY (Jmol). You should be viewing the crystal structure using Jmol, an open source Java viewer for chemical structures. Refer to your lab report for instructions on how to view molecules in Jmol. Learn about Jmol here.
Chemists use chemical naming rules, special equipment, computer visualization programs, and their imaginations to represent a molecule because we really can't "see" them.
Here are different ways to describe VANILLIN, a flavoring used in baking.
Chemical names: vanillin, 4-hydroxy-3-methoxy-benzaldehyde, 4-Oxy-3-methoxy-benzaldehyd, 4-Hydroxy-3-anisaldehyde, vanillaldehyde
Molecular formula: C8H8O3
Structural formula: CH3O(OH)C6H3CHO
Description/Use: white or very slightly yellow; pleasant odor and taste. Used as a flavoring agent.
Structure: |
Structure with C and H: |
Ball & Stick:
|
Spacefill:
|
We will use the traditional color scheme to represent C, H, N, and O atoms in our jelly bean molecules. This scheme was originally used in 1865 by a German chemist named August Wilhelm von Hofmann. His lecture entitled "On the Combining Power of Atoms" is the first recorded use of physical ball-and-stick molecular models in a lecture. See http://en.wikipedia.org/wiki/August_Wilhelm_von_Hofmann. This coloring scheme is also the "CPK" coloring convention used for molecular modelling. There is less standardization of other atom colors.
A. Time to build your jelly bean molecule!
These are the rules we will use to build jelly bean molecules:
| Element | Element Symbol |
Jelly Bean Color |
Number of Bonds |
|---|---|---|---|
| Carbon | C |
black |
4 |
| Hydrogen | H |
white |
1 |
| Nitrogen | N |
blue |
3 |
| Oxygen | O |
red |
2 |
| Bromine | Br |
brown-red |
1 |
| Fluorine | F |
yellow green |
1 |
| Chlorine | Cl |
green |
1 |
- Get a molecule card from Emily.
- Write down chemical name, molecular formula, element names, and number of elements of your molecule on your lab report.
- Gather all the jelly beans and toothpicks you need to make your molecule.
- Build your jelly bean molecule. CAUTION!!! Be careful not to poke yourself with your toothpicks. Use the paper clips to poke holes in your jelly benas equal to the number of bonds (toothpicks) you need for your atom.
B. Find the structure image of your molecule on this chemical structures site: Dave Woodcock's Molecular Models: Formula Index. Use Jmol to view it. Does it look like the molecule you built?
C. Complete Part 2 of your Lab Report.
Interesting Molecule Sites
- Firefly luciferase - an enzyme which catalyzes a reaction between luciferin and oxygen in which most of the energy is transformed into light (see Wikipedia luciferase article). View the enzyme in the Protein Data Bank (1LCI).
- Common Molecules Collection
- Atlas of Macromolecules
- Library of 3-D Molecular Structures
- Molecular Models, by Dr. Dave Woodcock, Okanagan University College
- Molecular Graphics, Wikipedia
- American Chemical Cociety Molecule of the Week
- Chemical of the Week, Science is Fun, Bassam Z. Shakhashiri (UW-Madison Chemistry Department)
- Protein Data Bank
Campus Technology Sites
Glossary
Atom = smallest unit of an element that can
exist as a stable, independent particle.
e.g. Gold (Au), Silver (Ag), Neon (Ne), one color of jelly bean
Chemistry = science of matter ("stuff") and how stuff changes from one form to another. Chemists study nature at the atomic level.
Compound = made up of 2 or more element; has its own properties; fixed combination of elements.
Element = composed of only 1 type of atom
Matter = anything that takes up space and has mass [quantity; resistance to acceleration]
Mixture = physical combination of 2 or more substances that may be present in variable amount
Molecule = smallest unit of a compound that
has properties of that compound
e.g. table sugar (sucrose = C12H22O11),
water (H2O), Oxygen (O2)
Jelly Bean Information, Activities, & Recipes
Images
Information
Jelly Belly home page. http://jellybelly.com
Take a virtual tour of the Jelly Belly factory, find a recipe for "blueberry muffin" flavor, view the Jelly Belly Museum of Art.
Activities
- Neuroscience for kids (taste activities with jelly beans)
- Studying Our Senses (hands-on activity)