Canadian Postal Code Database. Get all Canadian Postal Codes and their information in one easy to use database. 2010 Census Database. Get the 2010 Census data in an easy to use format for all summary levels: National, State, COunty, City, and Congressional District. Area Code Database.
Indicator Definition. A chemical indicator is a substance that undergoes a distinct observable change when conditions in its solution change. This could be a color change, precipitate formation, bubble formation, temperature change, or other measurable quality.
Universal Indicator Definition. A particular type of acid-base indicator is a universal indicator, which is a mixture of multiple indicators that gradually changes color over a wide pH range. The indicators are chosen so mixing a few drops with a solution will produce a color that can be associated with an approximate pH value.