Atoms with unpaired electrons, known as ____, are dangerous because they ____.

A) free radicals; damage biological molecules
B) ions; are unstable
C) radioisotopes; damage electron orbitals
D) free radicals; are inert
E) radioisotopes; cannot fill their electron shells

Free Radicals

Highly reactive molecules with unpaired electrons that can cause cell damage, implicated in aging and various diseases.

Ions

Atoms or molecules that have gained or lost one or more electrons, resulting in a net electric charge.

Radioisotopes

Isotopes of an element that are radioactive; they can be used in scientific research, medicine, and industry.