What are atoms made up of?

Atoms are made up of protons, neutrons, and electrons. Protons and neutrons reside in the nucleus at the center of the atom, while electrons orbit around the nucleus in what is often described as an electron cloud. Protons are positively charged, neutrons have no charge, and electrons are negatively charged. The interactions between these particles and their respective charges are fundamental to the structure and behavior of the atom.

This composition is crucial for understanding how atoms interact with one another to form molecules and how they participate in chemical reactions. For instance, the number of protons in an atom determines its atomic number, which defines the element. Electrons play a vital role in chemical bonding and reactions due to their negative charge, allowing for electrical interactions with other atoms.

The other combinations listed include particles that either do not contribute to the standard understanding of atomic structure (like photons, which are particles of light), or include particles that are not part of an atom's structure (like positrons and neutrinos). Understanding the correct composition of atoms is foundational for further studies in physics, chemistry, and related fields.