New Articles and Resources

By Anne Marie Helmenstine, Ph.D., About.com Guide since 2001

What Is The Difference Between Diffusion and Effusion? Created: Friday, May 25, 2012 Updated: Friday, May 25, 2012
A when a volume of gas is opened to another volume with less pressure, the gas can either diffuse or effuse into the container. The main difference between diffusion and effusion is the barrier bet...
How To Make a Roman Candle - Easy Homemade Roman Candle Firework Project Created: Friday, May 25, 2012 Updated: Friday, May 25, 2012
A Roman candle is a relatively simple firework that shoots fireballs into the air. Here are instructions for how to make a homemade Roman candle.
What Is The Formula For Graham's Law of Diffusion and Effusion? Created: Friday, May 25, 2012 Updated: Friday, May 25, 2012
Graham's law expresses the relationship between the rate of diffusion or effusion of a gas and its molar mass.
Lab Notebook - How To Keep a Lab Notebook Created: Friday, May 25, 2012 Updated: Friday, May 25, 2012
A lab notebook is your primary permanent record of your research and experiments. This is a list of guideline that explains how to keep a lab notebook.
Lab Notebook Created: Friday, May 25, 2012 Updated: Friday, May 25, 2012
A lab notebook is the primary permanent record of a researcher's laboratory work.
Chemical Reaction Classification Quiz - Test Your Knowledge of Types of Chemical Reactions Created: Thursday, May 24, 2012 Updated: Thursday, May 24, 2012
There are many different types of chemical reactions. There are single and double displacement reactions, combustion, decomposition reactions and synthesis reactions. See if you can identify the ty...
Kastle-Meyer Test To Detect Blood Created: Thursday, May 24, 2012 Updated: Friday, May 25, 2012
The Kastle-Meyer test is an inexpensive, easy and reliable forensic method to detect the presence of blood. Here is how to perform the test.
How To Make Kastle-Meyer Solution Created: Thursday, May 24, 2012 Updated: Thursday, May 24, 2012
The Kastle-Meyer test is a simple, reliable and inexpensive test to detect blood. Here is how to prepare the Kastle-Meyer solution used for the forensic test.
Asphaltic Definition Created: Thursday, May 24, 2012 Updated: Thursday, May 24, 2012
This is the definition of asphaltic.
Chemical Reaction Classification Practice Test Created: Wednesday, May 23, 2012 Updated: Thursday, May 24, 2012
There are many different types of chemical reactions. There are single and double displacement reactions, combustion reactions, decomposition reactions and synthesis reactions. See if you can ident...
Asphalt Definition Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is the definition of asphalt.
Naphthenes Definition Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is the definition of naphthenes.
Crude Oil Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is a sample of crude oil or petroleum.
Petroleum Composition - Chemical Composition of Petroleum Created: Wednesday, May 23, 2012 Updated: Thursday, May 24, 2012
Petroleum or crude oil is a complex mixture of hydrocarbons and other chemicals. Here is a look at the properties and chemical composition of petroleum.
What Is The Formula For The Combined Gas Law? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
The combined gas law examines the behavior of a constant amount of gas when pressure, volume and/or temperature is allowed to change.
Petroleum Definition - Crude Oil Definition Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is the definition of petroleum, also known as crude oil.
What is Dalton's Law of Partial Pressures? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
Dalton's law of partial pressures is used to determine the individual pressures of each gas in a mixture of gases.
What Is The Formula For Gay-Lussac’s Law? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
Gay-Lussac's Law is a special case of the ideal gas law. This law only applies to ideal gases held at a constant volume allowing only the pressure and temperature to change.
What Is Petroleum Jelly? - What Is Petroleum Jelly Made Of? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
Petroleum jelly or petrolatum was discovered as a paraffin-like material coating oil rigs. Since then, it has been used in various ointments and as a lubricant. Here is a look at what petroleum jel...
What Is The Formula For Boyle's Law? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
Boyle's Law is a special case of the ideal gas law. This law only applies to ideal gases held at a constant temperature allowing only the volume and pressure to change.
What Is the Boiling Point of CCl4 or Carbon Tetrachloride? - CCl4 or Carbon Tetrachloride Boiling Point Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is a look at the boiling point of carbon tetrachloride, also known a CCl4 or carbon tet.
What Is The Formula For Charles' Law? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
Charles' Law is a special case of the ideal gas law. This law only applies to ideal gases held at a constant pressure allowing only the volume and temperature to change.
Chemical Formula for Sugar - What Is the Chemical Formula of Sugar? Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is the chemical formula for table sugar, which is sucrose.
SpaceX Dragon - Falcon 9 Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
SpaceX Dragon - Falcon 9
SpaceX Dragon Falcon 9 Launch Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
SpaceX Dragon / Falcon 9 lifts off from Launchpad 40 at Cape Canaveral, Florida on May 22, 2012.
Valences of the Elements Created: Wednesday, May 23, 2012 Updated: Wednesday, May 23, 2012
This is a table of element valences.
NFPA 704 - What Is NFPA 704 or the Fire Diamond? Created: Wednesday, May 16, 2012 Updated: Friday, May 18, 2012
You probably have seen NFPA 704 or the fire diamond on chemical containers. Here is a look at what NFPA 704 is and what the colors and codes on the diamond mean.
NFPA 704 Placard or Sign Created: Sunday, May 13, 2012 Updated: Sunday, May 13, 2012
This is an example of a NFPA 704 warning sign. The four colored quadrants of the sign indicate the types of hazards presented by a material.
How to Make Napalm B - Chemical Synthesis of a Gelled Sol Created: Saturday, May 12, 2012 Updated: Sunday, May 13, 2012
Napalm B, more usually just called napalm, is an example of a gelled sol. This easy napalm synthesis is an interesting introduction to sols and gels.
Chemical Storage Color Codes - J. T. Baker Storage Code Colors Created: Saturday, May 12, 2012 Updated: Sunday, May 13, 2012
This is a table of chemical storage code colors, as devised by J. T. Baker. These are the standard color codes in the chemical industry.
Chemical Composition of Vinegar - What Is the Chemical Composition of Vinegar Created: Saturday, May 12, 2012 Updated: Saturday, May 12, 2012
This is a look at the chemical composition of vinegar.
Plastic Sulfur - Simple Sulfur Polymer Demo Created: Saturday, May 12, 2012 Updated: Saturday, May 12, 2012
Did you know you can make a polymer from an element? Turn ordinary sulfur into rubbery plastic sulfur and then back into its brittle crystalline form.

A part of The New York Times Company.