Which term refers to a negatively charged particle much smaller than an atom?

Which term refers to a negatively charged particle much smaller than an atom?

• A. Muon
• B. Proton
• C. Electron
• D. Neutron

Answer: (C)

The key idea is a negatively charged particle that is much smaller than an atom. That description points to the electron. Electrons carry a negative elementary charge and have a mass far smaller than protons or neutrons, about 1/1836 of a proton’s mass. They orbit the nucleus and are responsible for chemical bonds and electricity. Protons are positively charged and reside in the nucleus, while neutrons are neutral, so they don’t fit the “negatively charged” part. The muon is also negatively charged but is much heavier than the electron and doesn’t form part of ordinary atoms, so it isn’t what’s described here.

The key idea is a negatively charged particle that is much smaller than an atom. That description points to the electron. Electrons carry a negative elementary charge and have a mass far smaller than protons or neutrons, about 1/1836 of a proton’s mass. They orbit the nucleus and are responsible for chemical bonds and electricity. Protons are positively charged and reside in the nucleus, while neutrons are neutral, so they don’t fit the “negatively charged” part. The muon is also negatively charged but is much heavier than the electron and doesn’t form part of ordinary atoms, so it isn’t what’s described here.