Ions and ionic bonding
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What this model shows
Salt melts at 801 °C. A crucible over a hot Bunsen flame only just reaches that, and molten salt is dangerous, so the molten test here is virtual. Schools show molten conduction with a compound that melts at a lower temperature, as a teacher’s demonstration in a fume cupboard.
When ions carry a current through a melt or a solution, new substances also form at the rods. That’s electrolysis, in topic 4, and this experiment leaves it out. Real pure water has a very small number of ions, far too few to light a bulb.
The ions and molecules in the magnifier aren’t to scale, and their colours are only labels. The crucible is drawn cut open so you can see the rods in the salt. The waits are shortened.
With reduced motion, each test finishes at once and the particles in the magnifier stay still.
Select a piece of equipment, on the bench or here, to read about it in the card.