Crystal structure

Crystal structure is like packing a lot of boxes together. Every atom or molecule in a crystal has a specific place it needs to go, just like how when you are packing boxes, you have to fit them together in a certain way. In the same way that different types of boxes - like cardboard, plastic or wood - need to fit together differently to pack them properly, atoms and molecules in crystals need to fit together in specific ways. Just like if our boxes had all different shapes and sizes, so do atoms and molecules in crystals. So all the small pieces of a crystal have to fit together just right to make the crystal structure look the way it does.