Answer
D
Work Step by Step
Isotopes are atoms that can exist in different types. Their proton and electron numbers are the same, their neutron numbers are different. The same elements with different isotopes have different masses.
Atoms are made of protons, neutrons, and electrons. Protons and neutrons make up the nucleus. Protons and electrons have the same charge, but they are opposite.
Atoms contain the same number of protons and electrons; therefore, they are neutral. Ions are electrically charged particles. Ions are produced by removing electrons from a neutral atom to get a positive ion or adding electrons to a neutral atom to get a negative ion.
Free radicals are atoms or molecules that are highly reactive with other cellular structures because they contain unpaired electrons. They can cause damage to parts of cells such as proteins, DNA, and cell membranes by stealing their electrons through a process called oxidation.