Just Say No to Abuse Declaring War on Terrorism. Well, wonder no more. Just click on the link. This site does not just answer your question but provides links to other web sites to supplement their answer. Many of the terms and concepts are also links.
Salt has quite a history.
If you read the articles on salt and blood pressure and diet, please remember these people are promoting salt. Best to check with your doctor first. Nonetheless, it is an excellent site detailing how salt is mined, what it is used for and how kids can use it to have fun. The amount of information presented here is amazing. But that does not mean we can't have fun.