Video Transcript
Which statement regarding the two atoms in the diagram is correct? (A) They are different atoms, as they have different numbers of neutrons. (B) They are identical atoms. (C) They are identical atoms, even though they have different numbers of neutrons. (D) They are different atoms, as they have different numbers of protons. Or (E) they are different atoms, as they have different numbers of protons and neutrons.
To answer this question, we need to identify which statement about the two atoms is correct. Looking at the statements, we can see that we need to identify if the atoms are identical or different. And the statements suggest that we can determine whether the atoms are identical or different by looking at the number of neutrons and protons.
So let’s start by counting the number of protons and neutrons in each atom. The atom on the left has five protons and six neutrons, while the atom on the right has five protons and five neutrons. Atoms of each element contain a different number of protons in their nucleus. So the number of protons an atom contains can be used to identify the element. As both of these atoms contain five protons, they are both atoms of the element boron. But although these atoms are atoms of the same element and will share nearly identical chemical properties, they are not identical atoms. This is because the atoms have a different number of neutrons. This will affect the mass of the atom and its nuclear stability. We call atoms that have the same number of protons but a different number of neutrons isotopes.
With this information in mind, let’s take a look at the answer choices. We can eliminate answer choices (B) and (C) because the atoms are not identical. We can also eliminate answer choices (D) and (E) because the atoms have the same number of protons. This leaves us with answer choice (A). So the statement regarding the two atoms in the diagram that is correct is (A). They are different atoms, as they have different numbers of neutrons.
