ChemQuantum is an app designed to help the user become successful at writing the four common diagrams chemists use to represent the electronic structure for the shell of any atom. An option for practicing the 20 anomalous electron arrangements for non-aufbau elements is included. The most used diagrams are Orbital-Filling Diagrams, Electron-Configuration Diagrams, Electron-Dot Diagrams and Quantum Numbers. The user is able to select an area of the periodic table on which to focus as well as the diagramming method to be practiced. In each case, unlimited completion attempts are allowed. A running score is provided along with the results for each problem attempted that can be archived as an email. The answer to any problem is a button touch away. The app’s accepted answer may be compared to the user’s answer on the same screen by selecting “Give Up”. Selecting “Give Up” forfeits the unlimited completion attempts for the presented problem, but can be a useful method for learning each electron diagramming process. In-app help is provided in the form of an explanation with examples of how to write Orbital-Filling Diagrams, Electron-Configuration Diagrams, Electron-Dot Diagrams and Quantum Numbers. The accepted answers are based on the element’s periodic table position. Experimental or exceptions to predicted electron arrangements are not considered with this app. A 3-dimensional scrollable animation for each element’s overlapping surface orbitals is provided by touching the “Shape” button, when the app’s accepted answer is entered. The original version of this app The Quantum Atom was written by Pat Thayer and marketed by Thayer ChemSoftware LLC and has been used in chemistry classes for nearly two decades. Short videos of the ChemQuantum app in operation can be viewed at chemistryapp.org.