Benchmark 4G
The Physical Setting: Forces of Nature
Grades 9-12, page 96

Electromagnetic forces acting within and between atoms are vastly stronger than the gravitational forces acting between the atoms. At the atomic level, electric forces between oppositely charged electrons and protons hold atoms and molecules together and thus are involved in all chemical reactions. On a larger scale, these forces hold solid and liquid materials together and act between objects when they are in contact--as in sticking or sliding friction.
 

NSES Content Standard B   Physical Science: Structure of atoms  Grades 9-12, page 178  Matter is made of minute particles called atoms, and atoms are composed of even smaller components. These components have measurable properties, such as mass and electrical charge. Each atom has a positively charged nucleus surrounded by negatively charged electrons. The electric force between the nucleus and electrons holds the atom together.  NSES Content Standard B   Physical Science: Motions and forces  Grades 9-12, page 180  Between any two charged particles, electric force is vastly greater than the gravitational force. Most observable forces such as those exerted by a coiled spring or friction may be traced to electric forces acting between atoms and molecules.