Interactive chemistry
The interactive activities are in English.
Atomic mass and isotopes
Enter isotope masses and abundances. The calculator finds the weighted average atomic mass.
Balancing chemical equations
Change the coefficients until each element has the same atom count on both sides. The live tally identifies any imbalance.
Bond polarity
Compare two atoms’ electronegativities. See how their difference affects electron sharing in a bond.
Electron configuration
Choose an element and follow how electrons fill orbitals. Compare the configuration with its shell diagram.
Bohr model
Choose an atomic number from 1 to 118 and inspect the electron shells. Notice the outer-shell electron count.
Interactive periodic table
Select an element to inspect its group, block and electron configuration. Change the color scheme to spot patterns.
Bonding types
Pick two elements and compare electronegativities. The result suggests a bond type, though real bonds do not follow a single rigid threshold.
Lewis structures
Choose a molecule and arrange bonding and lone electron pairs. Count valence electrons and check octet-rule exceptions.
Stoichiometry step by step
Choose a reaction and read mole ratios from its coefficients. Convert reactant amounts into predicted product amounts.
Molecular geometry
Select a molecule or a count of bonds and lone pairs. Compare its shape and angles using the VSEPR model.
Molecule builder
Add atoms and connect them into molecules. See how composition and bonding determine the resulting structures.
Noble gases
Compare group 18 elements, their properties and shells. Select a gas and inspect the importance of its outer shell.
Periodic table game
Pick a set of elements and click the one requested. Missed elements return so you can practice them again.
Periodic trends
Switch among electronegativity, ionization energy and electron affinity. Look for patterns across periods and down groups.
States of matter
Add heat to ice and follow the temperature through melting and boiling. Flat parts of the heating curve mark phase changes.
Gas laws
Change pressure, volume, temperature or amount of gas and examine the equations. Graphs help compare the different laws.
The mole
Enter a formula and a mass or substance amount. Follow the conversion steps between grams, moles and particles.
Particle box
Heat, cool or compress particles in a box. Watch how motion and collisions affect pressure and phase.
pH scale
Select a value to compare acids, neutral solutions and bases. The calculator links pH with hydrogen-ion concentration.
Reaction types
Choose a reaction pattern and predict products. Compare synthesis, decomposition, replacement and combustion.
Valence electrons
Select a main-group element and inspect its Lewis symbol. Connect its table position with its valence-electron count.