What is a positively charged subatomic particle?

Hint: There are three important types of subatomic particles in an atom i.e. protons, neutrons and electrons. Among these, protons are positive, neutrons are neutral and electrons are negatively charged. Protons and neutrons are present in the center of the atom called the nucleus.

Complete answer:
Protons are particles which have a positive charge and are massive nuclear particles. The number of protons present in the nucleus of an atom define the atomic number which is the identity of that element. The sign of the charge of the proton is generally positive. It should be noted that the nuclear proton has an opposite electronic charge to that of an electron. This designation helped quantum chemists from getting the wrong sign in their answer simply because they counted up the number of electrons wrong.
Therefore, the positively charged subatomic particles present in an atom are called protons.

Note:
The contribution of a proton to the total weight of an atom is one atomic mass unit. Electrons are subatomic particles which are negatively charged and are almost massless particles. Neutrons are neutral subatomic particles which are present in the nucleus of an atom. They have no electric charge. Atom is the smallest unit into which matter can be divided without releasing any electrically charged particles. They are considered as the basic building blocks of chemistry. They are the smallest unit of matter which have the characteristic properties of a chemical element. Due to their very small size, they are not visible to the human eye.