Information on the dietary and nutritional significance of selenium from an authoritative source.

Good information on selenium with respect to the environment and health.

Elements in the same group in the periodic table have similar chemical properties. This is because their atoms have the same number of electrons in the highest occupied energy level. Group 1 elements are reactive metals called the alkali...

A covalent bond is formed between non metal atoms, which combine together by sharing electrons. Covalent compounds have no free electrons and no ions so they don't conduct electricity.

This section of the lesson module focuses on covalent bonds, which are formed between non-metal atoms that share a pair of electrons. It includes links to a video and a test. Other types of chemical bonds are covered elsewhere in the...

If you've ever wondered how things are made - products like candy, cars, airplanes, or bottles - or if you've been interested in manufacturing processes, like forging, casting, or injection molding, then you've come to the right place....

Description of graphite and its basic properties. Also a comparison to diamond and how they differ.

Basic statistics, history, and properties of the halogen element, astatine.

A general overview of the non-metal element Hydrogen.

A description of the non-metal element Oxygen.

A brief description of the non-metal element, Phosphorus.

A brief description of the non-metal element Sulfur.

A brief look at the non-metal element Selenium.

A description of the non-metal element Nitrogen.

Describes the organization of the periodic table of elements and the different groups in it.

Looks at the chemical and physical properties of halogens.

Learn about the characteristics, chemical and physical properties, and uses of halogens.

Explains what intramolecular and intermolecular forces are and the different types for each. Includes lots of examples.

A clear explanation of the facets involved in electroplating, the materials and surfaces, the sequence of operations.

The Upper Harz mining water management system, which lies south of the Rammelsberg mines and the town of Goslar, has been developed over a period of some 800 years to assist in the process of extracting ore for the production of...