This edition has 4 Levels to start you off and an Editor, which allows you add and edit the levels.
Learn to write chemical formulas by dragging and dropping or double-clicking the ions.
The Test Mode randomly selects ions from the Level you have chosen.
To Make the Test More Challenging:
* Include or exclude Atom Counting Questions,
* Testing can be done with or without the extra pressure of time,
* You can set how long the timed test will run for,
* Hide or Show the positive and / or negative ions
A Top Scores window shows the best scores to date.