Video Transcript
Which particles can be found in the nucleus of an atom? (A) Protons and electrons, (B) protons and neutrons, (C) neutrons and electrons, (D) positrons and electrons, or (E) positrons and neutrons.
Atoms are the basic unit or building block of matter. Atoms are composed of three types of subatomic particle: positively charged protons, neutral neutrons, and negatively charged electrons. These particles are found in two main regions inside of an atom. In the center of the atom, we find the nucleus. Compared to the size of the atom, the nucleus is very small, with an atom being roughly 10,000 times wider than the nucleus. Despite this, most of the mass of an atom is found in the nucleus. This is because both protons and neutrons, which are significantly more massive than electrons, are found in the nucleus. Outside of the nucleus is a large region of space called the electron cloud. As the name suggests, this is where we can find the electrons in an atom.
We now know that the particles that can be found in the nucleus of an atom are the protons and neutrons, answer choice (B).
