Free Science

Lab and homework helpers for the sciences: chemical equation balancer (exact fractional math), molarity/dilution, molecular weight with a 118-element table, projectile motion, Ohm's law, resistor color codes, voltage dividers, electrical power, density, speed/distance/time, and wind chill / heat index / dew point.

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About these science

Every tool below is free, works in your browser, and needs no account.

How does the equation balancer work?
It sets up the atom-balance equations and solves the null space with exact fraction arithmetic — so H₂ + O₂ → H₂O correctly yields 2, 1, 2.
Does the molecular weight tool know every element?
Yes — all 118 elements with standard atomic weights, plus a per-element breakdown of your molecule.
Are units handled?
Each tool states its expected units up front and converts where it matters — no silent unit confusion.