The smallest components of the nucleus of an atom are protons and electrons. Particles and antiparticles can materialize out of energy. Particle physicists need larger accelerators in order to investigate larger objects. Magnets are used in circular accelerators to make the particles move faster. Work done by particle physicists at accelerators is helping us understand the very early development of the universe.
Gravity is the strongest of the fundamental forces of nature.
There are at least one hundred different subatomic particles. All known matter is made of leptons and quarks. Friction is one of the fundamental forces of nature.