Question detail
An isotope of carbon has a mass number of 14 and an atomic number of 6. How many neutrons does this isotope contain?
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
MCQ
Type
practice
Style
Topic
Atomic structure
Question
- A. 6
- B. 8
- C. 14
- D. 12
Answer
8
Explanation
The mass number (14) is the sum of protons and neutrons. The atomic number (6) indicates there are 6 protons. Therefore, neutrons = mass number - atomic number = 14 - 6 = 8.
Common mistake
Misidentifying Neutrons from Mass Number
Students often subtract the atomic number from the mass number to find the number of neutrons, but then forget to adjust for the ion’s charge when calculating electrons.
Remember that the number of neutrons is always mass number minus atomic number, independent of charge. The electron count is atomic number minus the ion’s charge (negative charge means +1 electron, positive charge means –1 electron).
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.