© David Kaplan.
All material we experience—solid, liquid, or anything in between—is held together by the electromagnetic force. While this glass of water may be essentially neutral, and has approximately the same number of positive and negative charges, the water is made of molecules, which are made of atoms, which are made of charged particles—protons and electrons. These particles not only attract each other within the atoms through the electromagnetic force, but from atom to atom, and molecule to molecule. The attractions and repulsions deform the atoms and molecules in such a way that the net result is an attraction between molecules, and thus macroscopic materials form. (Unit: 2)