What Nuclear Physics Studies
From Atoms to Nuclei
The big picture
Matter is made of atoms. Each atom has a tiny, dense center called the nucleus, surrounded by electrons. Nuclear physics focuses on the nucleus itself: what it is made of, how it stays together, and how it can change.
Why nuclei matter
Nuclei are the source of nuclear energy, radioactive decay, medical imaging, cancer therapy, and much of the energy produced in stars.
Atoms in one sentence
An atom is mostly empty space, but almost all of its mass is concentrated in the nucleus.
Core terms
Atomic scale vs nuclear scale
Atom
- Size is about
- Contains electrons and a tiny nucleus
Nucleus
- Size is about
- Contains protons and neutrons
What does nuclear physics mainly study?
Nuclear physics focuses on the nucleus and processes that involve nuclear structure or nuclear transformations.
Correct answer: The nucleus, its structure, and its changes
Name the two main particles found in the nucleus.
The nucleus is built from protons and neutrons, which are often called nucleons.
Correct answer: protons and neutrons
Why is an atom mostly empty space?
The nucleus is tiny relative to the atom, so most of the atom's volume is empty space.
Correct answer: Because the nucleus is extremely small compared with the atom