A(n) ___ is the smallest particle to which an element can be reduced yet still retain the characteristics of that element.

The term that refers to the smallest particle of an element that retains its chemical properties is 'atom.' Atoms are the basic building blocks of matter and represent the individual characteristics of an element, including its unique properties such as atomic number, mass, and reactivity. Each element on the periodic table is defined by its atoms, and these atoms consist of protons, neutrons, and electrons. When an atom is broken down further, it loses its elemental properties, which is why it is recognized as the smallest unit of an element.

While molecules, ions, and particles are essential concepts in chemistry, they encompass structures made up of one or more atoms or carry different properties that do not specifically represent a single element. Molecules consist of two or more atoms bonded together, ions are charged particles formed by the loss or gain of electrons, and particles can refer to a broader range of small units, including subatomic particles. Therefore, the atom stands out as the correct answer in this context.