What is a negatively-charged subatomic particle that resides outside of the nucleus in the electron orbital, lacks functional mass, and has a negative charge of - 1?

Electron

Explanation:

The electron

Explanation:

The atom essentially has two parts, the positive core and the orbits. The positive core contains two of the subatomic particles. These are the neutrons and the protons. It is a positive core because while the proton is positively charged, the neutron is chrageless. Hence, it is the proton only that contributes to the overall charge of the nucleus.

Since the atom is adjudged you be electrically neutral, to balance the excess positivity at the core, there must be a corresponding subatomic particle with negative charges. This is where the electron comes in. The electron has all the properties listed in the question above.