chemPad Questions

Use chemPad to enter chemical formulas and equations that are automatically displayed in correct chemical notation.
The chemPad tool includes a row of buttons at the top, a formatted display area in the middle, and a text entry box at the bottom.

chemPad accepts chemically equivalent responses that are entered in a different sequence than the key, and also provides constructive feedback to your students so they know, for example, if the equation they submitted was not balanced, or if an element was substituted. Without giving away the answer, this feedback helps your students to identify their mistakes and to learn while they are completing their assignments.

Type your answer or click buttons to formulate your response in the text entry box. chemPad automatically updates the display area to show the formatted chemical notation.

The formatted chemical notation in the display area helps you to know that what you are typing represents the chemical formula or equation you intend to submit for your response.

Use the chemPad buttons as a way to enter some kinds of notation.

You can pause the pointer over any button to see its description.  

To enter this

Click this

Type this


 susbcript button
_ (underscore)


 superscript button
^ (caret)

Forward Reaction Arrow

 forward reaction arrow button

Equilibrium Reaction

 equilibrium reaction arrow button

Reverse Reaction Arrow

 reverse reaction arrow button

Lowercase Greek letters such as α, β, δ

 Greek button

The lowercase name of the letter, such as alpha, beta, delta

Uppercase Greek letters such as Δ, Σ, Ω

 Greek button

The capitalized name of the letter, such as Delta, Sigma, Omega

Stacked Fraction


Dot (·)

. (period) or *
  • chemPad is designed to minimize your need to add formatting to your answer. For most questions, you do not need to indicate to chemPad where to end a subscript or superscript, or to specifically delimit special symbols like arrows.
  • Type spaces where they belong in your notation, such as between quantum levels in an electron configuration and between chemical formulas and arrows or plus signs in reaction equations.
  • Typing an alphabetic character or a space ends a subscript or superscript. For example, type H_2O to display H2O, or Na^+ + Cl^- to display Na+ + Cl-.
  • To type advanced notation such as general formulas and equilibrium equations, enclose the content of a superscript or subscript in braces {}. For example, type K_{c} = [CO_2] to display Kc = [CO2].
  • The same rules are used to display the formatted notation and to score your response, so ensure that your formatted notation represents the answer you want to submit.