Exam-style question
Try this first
Which of the following statements is true about isotopes of the same element?.
- A.They have the same number of electrons but different numbers of protons.
- B.They have the same number of protons but different numbers of neutrons.
- C.They have the same number of neutrons but different numbers of electrons.
- D.They have the same number of protons and neutrons but different numbers of electrons.
Model answer
What a good answer should say
- They have the same number of protons but different numbers of neutrons.
Explanation
Why this works
Isotopes share the same proton number (defining the element) but differ in neutron number, leading to different atomic masses. This directly addresses the learning objective of explaining isotopes using neutron number.
Common mistake
No common mistake is linked to this question yet.