Which subatomic particles are negatively charged and found in all neutral atoms?

Electrons are the subatomic particles that carry a negative charge and are found in all neutral atoms. In an atom, electrons are located in the electron cloud surrounding the nucleus, which consists of protons and neutrons. In a neutral atom, the number of electrons is equal to the number of protons, resulting in no overall charge. Hence, because of their negative charge, they balance out the positive charge of the protons in the nucleus.

The presence of electrons is fundamental to the structure of atoms, influencing their chemical behavior and bonding properties. Additionally, while protons are positively charged and neutrons are neutral, neither of these contribute a negative charge. Ion pairs do not refer to specific subatomic particles but rather to ions that have gained or lost electrons, thus not fitting the context of this question regarding neutral atoms.