The term 'PHYSICS BITS' can be broken down into two crossword solutions: ATOMS (5 letters). ATOMS are the basic building blocks of all matter in the universe. They are composed of protons, neutrons, and electrons, and are the smallest particles that make up an element. Physics is the study of the physical world, and ATOMS are a fundamental part of this study. By understanding the structure and behavior of ATOMS, physicists can gain insight into the nature of matter and energy.