MCQ practice · SSC Chemistry Board questions · Chapter 3: Structure of Matter
How many protons does the Al³⁺ ion have?
Think it through first, then pick an option.
- a 10
- b 13
- c 16
- d 27
Answer and explanation
Correct answer: b 13
The proton number stays Z = 13 even in the ion; only the electrons change.
Why the other options are wrong
- a 10: 10 is the electron count (13 − 3); the protons do not change in an ion.
- c 16: 13 + 3 = 16 adds the charge by mistake; the charge changes electrons, not protons.
- d 27: 27 is the mass number, protons plus neutrons; the protons are 13.
More board questions on this topic
- Which carries the true identity of an atom?
- How many protons are in the nucleus of helium?
- An atom of an element has a protons, b electrons and c neutrons. What…
- How many neutrons does ⁵⁶₂₆Fe have?
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