uncharged particle located in the nucleus; the number of these that an atom has is equal to its mass number minus its atomic number

The correct answer is Neutron

Explanation:

As shown in the diagram the sub-particles in atoms are electrons, neutrons, and protons. From these, the two types of particles that are in the nucleus or center of the atom are neutrons and protons. Moreover, neutrons differ from protons because these are neutral or are not charged. According to this, the uncharged particles in atoms are neutrons.

Moreover, the number of neutrons can be calculated by subtracting the atomic number (number of protons) to the mass number (number of atoms and protons). For example, if in an atom the mass number is 12 (protons and neutrons)and the atomic number is 6 (number of protons), the neutrons are 6 (12 - 6 = 6). According to this, the correct answer is the neutron.