Which subatomic particles have a negative charge?

Electrons are the only subatomic particles that have a negative charge.

Outside of the nucleus, electrons are the negatively charged particles in atoms. An electron is a subatomic particle with a negative electric charge.  

In physical sciences, a subatomic particle is a particle that is smaller than an atom. According to the Standard Model of particle physics, a subatomic particle can be either a composite particle, which is composed of other particles (for example, a proton, neutron, or meson), or an elementary particle, which is not composed of other particles (for example, an electron, photon, or muon). Particle physics and nuclear physics study these particles and how they interact.

Explanation: Electrons are a type of subatomic particle with a negative charge. Protons are a type of subatomic particle with a positive charge. Protons are bound together in an atom’s nucleus as a result of the strong nuclear force

the answer to this question is 3.