When teaching electronic configuration, if it's a small class you can get each student in the class to be an electron. They can arrange themselves in different directions. It's really good if you've got steps in your classroom because you can demonstrate going up in energy. They face towards the front or the back of the room. If you simply tell them to think about parallel and antiparallel spins they come up with that themselves and it's really good when you can say, 'Yes, you came up with that yourselves.'
Use balloons to illustrate bonding pairs and electron pair repulsions leading to the determination of molecular shape For example, if you tie 6 balloons together, it automatically forms the octahedral shape. Then each time you pop one, they rearrange themselves to sequentially form the other shapes: trigonal bipyramidal, tetrahedral, trigonal planar and linear. It’s visually appealing, a concrete example and memorable for students. Also, popping the balloons wakes the students up!
Try demonstrating the reaction first, to show the macroscopic changes that occur, before introducing the equation. Copper in silver nitrate solution is a standard one. Explain it in terms of particles, the ions, atoms, show a video representation (for example from YouTube) of these changes, and then explain the whole thing in terms of the symbolic chemical equation to represent the overall change.
Something you can do visually in the lecture theatre is to take in some things you wish to connect and make up an item. Or in PhET, for example, there’s a little activity you can do making sandwiches and you can work out how much you need of which one and whether you’ve got something that’s there in excess or something that’s limiting. It's based on the molar ratios or the stoichiometric coefficients, which in turn are based on the number of moles reacting.
Take something into the lecture theatre, like a bag of pebbles - a whole lot that are the same size and make sure that it is visibly a kilogram (or another specified mass). Also have chickpeas or some other smaller and lighter thing. When you have a kilogram it’s really easily recognisable that there’re a lot more particles in the chick pea bag that there are in the pebble bag. You can’t show them a mole of something because it’s too many, but just use this to begin to unpack the idea that we’ve got a whole lot of tiny, tiny particles, much smaller than the ones in the demonstration.
For a demonstration of concentration versus total quantity: get three 100 mL graduated cylinders. And put a bit of food colouring in one and maybe dilute to 10 mL. Put an equivalent amount of food colouring in another and make it up to 30 and 100 mLs. It’s the same amount of food colouring in 10 mL, 30 mL, 100 mL. What will they look like? Dark, medium and lighter. Look down the top, what will they look like? Identical. It’s the same amount of molecules absorbing, blue, or whatever colour’s being absorbed.
Use physical and tactile experiences to demonstrate intermolecular forces. For example, If you stretch a plastic grocery bag (made of polyethylene), the length increases and the width decreases. This breaks apart the London Dispersion Forces (induced dipole-induced dipole interactions) and straightens out the polyethylene chains. The covalent bonds remain intact until the plastic rips.
You can get the students to physically feel that liquids are not compressible by giving them three closed syringes: one contains water, say 50 mL, that’s been put in the freezer to become ice; another syringe contains 50 mL of liquid water, and the other one is gas. Ask them to push the syringes and see what happens. They find they cannot push the syringes containing liquid or solid, even though they think there would be some space in the liquid one. The misconception is that liquids fall somewhere between solid and gas and so should be “a bit” compressible.
