Question

If isotopes are chemically alike but physically different, propose which subatomic particles are responsible for determining an element's chemical reactivity.

a) Protons
b) Neutrons
c) Electrons
d) Isotopes

Answer 1

The chemical reactivity of an element is determined by its electrons. Isotopes of an element have identical chemical behaviors due to having the same number of protons and electrons, but they may differ physically due to different numbers of neutrons.

Step-by-step explanation:

The subatomic particles responsible for an element's chemical reactivity are the electrons. Isotopes of an element have the same number of protons and the same number of electrons, which is why they exhibit the same chemical behavior regardless of the number of neutrons. This means that while isotopes differ in their mass due to a varying number of neutrons, they do not differ in their chemical properties. The different numbers of neutrons in isotopes make them physically different, such as different mass or stability, but it is the arrangement of electrons around the nucleus that determines how an atom will chemically react with other atoms.

Answering the review question, atoms that vary in the number of neutrons in their nuclei are called isotopes.