and they are different from the atoms of all other elements. For example, copper and gold are elements. A piece of gold contains only gold atoms. A piece of copper contains only copper atoms.

Let’s take chlorine as an example. It is positioned ... like chlorine gas, as elements. But these are very different from the isolated atoms depicted on the periodic table.

Examples of this are ... Earth's atmosphere with its two nitrogen atoms. Chemistry recognizes triple bonds between all ...