Usage - Pronoun-Antecedent Agreement. A pronoun is a word used to stand for (or take the place of) a noun. A word can refer to an earlier noun or pronoun in the sentence. Example:
A subatomic particle is a unit of matter or energy that's the fundamental makeup of all matter. According to modern atomic theory, an atom has a nucleus, which is its center, or core. The nucleus contains subatomic particles: protons and neutrons. Protons are positively-charged particles. Neutrons are neutral particles.
An atom is always charge less i.e it is neutral. An atom always refers to a single element. The atomic number of an element refers to the number of protons or electrons in it. This is because an atom always has equal number of electrons and protons. Protons are positively charged while electrons are negatively charged. Atoms also contain neutrons which are neutral. Proton, neutron and electron are called sub atomic particles. Neutrons and protons are called nucleons since they are in the nucleus of the atom. Charged species are called ions.