Some isotopes are unstable, or radioactive, meaning they will decay over time and turn into another isotope or stable element. In the interactive simulation, participants manipulate elements to create isotopes and gather information....

Assume the role of Canadian border control! The percent of alcohol and density of a solution are related. Young scholars use this fact to classify solutions by their alcohol content to determine if they meet Canadian import laws.

[Free Registration/Login Required] Manipulate graph data to see a representation of the percent composition of different compounds. Then answer a challenge question about the activity.

[Free Registration/Login Required] Students explore how percent abundances of different isotopes affect the average atomic mass for that given element. Students form connections between the average atomic mass and a person's body mass....