Isotoon explains chemistry by showing what atoms, electrons and molecules are doing. Ask about bonding, moles, equilibrium or pH and get a short animated video at the scale where the rule starts to make sense.
Most of chemistry happens at a size nobody can see, which is why the rules can feel arbitrary. Ask why something happens and see it at the level of atoms and electrons.
A mole is a counting unit, like a dozen, but for particles: 6.022 × 10²³ of them. Chemists use it because it links a mass you can weigh to the number of particles that react. One mole of a substance has a mass in grams equal to its formula mass, so 18 grams of water is one mole of water molecules. The coefficients in a balanced equation are ratios of moles, not of grams.
At equilibrium the forward and reverse reactions run at the same rate, so the concentrations stop changing. Le Chatelier's principle says that if you disturb that balance by adding a reactant, removing a product, or changing the pressure or temperature, the system shifts in the direction that partly undoes the change. Adding reactant pushes it toward products; heating an exothermic reaction pushes it back toward reactants.
Water is polar: its oxygen end carries a partial negative charge and its hydrogen ends a partial positive charge. Around a salt crystal, water molecules turn their oxygen ends toward the sodium ions and their hydrogen ends toward the chloride ions. When those attractions together outweigh the pull holding the ions in the lattice, the ions are carried off one at a time, each inside a shell of water molecules.
The ones marked 3D become a model you can turn, step through and tap.
Every claim is checked before anything is drawn, and every video lists its sources. See plans