Cooper cannot be broken down into a simpler substance since it is an element meaning it had its own atoms.
Acids are corrosive, which means they 'eat away' at other materials.
The green and black symbols refer to atoms, that make up the molecule of water, more specifically you can say that the 2 Hydrogen atoms are the black ones found outside, while the central atom, that is also green would be oxygen.
Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
