I dropped out of science and math in middle school but my son likes it. I once told him “all things, everything you see, are made of atoms” and he got excited by it. We spin around in circles as atoms and crash into each other to form compounds. I bought him a periodic table and every day he asks what this and that element are, what’s this column called etc.
Any info I give is from at chemistry textbooks and general science books from the library. We act things out wherever possible to make the knowledge fun and interactive. I can keep going this way, but maybe people have some suggestions on else we can do?