Moles from mass
For ages 15 to 18.

Mass over molar mass for eight everyday compounds.

What the sciences kits are

Biology, chemistry, physics, earth and space science, from primary science to university courses: processes in order, terms and their definitions, diagrams to label and click, calculations with units, and data read from tables and graphs. Some kits are made by rule (units, formulas, the periodic table); most are written from your own textbook.

Why they are built this way

Science is processes, structures and quantities, and each needs its own shape: a process is a sequence, a structure is a diagram to label, a quantity is a number with units and a tolerance. The kits use the shape the content needs, so a student is tested on what they know about the cell rather than on their reading of a stem.

How to use them

Use the sequence kits for cycles and mechanisms, the hotspot and labelling kits for anatomy and apparatus, and the numeric kits for calculations. Paste a chapter for questions in your course's own words. For revision, take the kits in study mode and let the re-tests space themselves.

Made by rule

This kit is made in code: every time it opens, the numbers, words or arrangements are drawn fresh from its rule, so the same kit taken twice is two different quizzes from one rule. There is no answer bank to find, and the practice never runs out. Each question carries its explanation, shown at once in study mode.

The shape: maths expression

An equation or expression typed and checked: algebra, calculus and any answer that is a formula rather than a number.

Expressions, numbers and single-form answers are marked by rule, with tolerances and half-credit tolerances where you set them. A typed expression or chemical equation is compared sign for sign, with spacing ignored, so each form you accept is listed, and a slip that would be forgiven in a word is never forgiven here; working and code are marked by a reader against your rubric, step by step.

Taking it

Open it in study mode for the answer and the explanation after each question, and a retry of only what you missed. Switch to exam mode for the real conditions. It comes due again in a few days; the dashboard shows what is due and what you missed last time. Share it with a code for a class, print it as a paper, or host it on a screen for a room.