US Geological Survey
Usgs: Arsenic in Ground Water in the United States
This page discusses the presence of arsenic (chemical symbol As) in ground water in the United States. Also provides many links to other sites about arsenic (especially in drinking water.)
Thomas Jefferson National Accelerator Facility
Jefferson Lab: Reading Passages: Liquid Nitrogen
Read and fill in the blanks of this passage explaining liquid nitrogen. Each blank has a dropdown menu with choices. When you finish, click CHECK MY ANSWERS. If you pick a wrong answer, the right answer will be displayed along with your...
Other
Chemistry Resources: The Nitrogen Family
This site provides a photograph and information on all the elements of the Nitrogen family.
Centers for Disease Control and Prevention
Centers for Disease Control: Antimony: Atsdr Fact Sheet
This page describes the chemical element antimony (chemical symbol Sb) and gives detailed information about its effects on human health and the environment.
Other
Algone: The Nitrogen Cycle
This resource gives a brief overview of the nitrogen cycle, dealing especially with the nitrogen cycle in aquariums.