A substance that speeds up a chemical reaction without being consumed itself. It's like having an extra pair of hands helping you disassemble your Lego structure faster.
This is when energy (usually heat) is absorbed during a chemical reaction. It's as if you needed to use some effort (energy) to pull apart those tightly stuck Lego pieces.
This represents what happens in any given chemical reaction – it shows what you started with (the reactants) and what you ended up with (the products). In our analogy, it would show your initial Lego structure and then all the separate pieces after disassembly.