MCQ practice · SSC Chemistry Board questions · Chapter 3: Structure of Matter
How many valence electrons does Cu have?
Think it through first, then pick an option.
- a 1
- b 2
- c 9
- d 10
Answer and explanation
Correct answer: a 1
Cu is 2, 8, 18, 1: one electron in the last shell, so 1 valence electron.
Why the other options are wrong
- b 2: 2 would be right if N held two (as in Zn), but copper moves one 4s electron to 3d, leaving 1 in N.
- c 9: 9 is scandium's M shell count; it has nothing to do with the last shell.
- d 10: 10 is the 3d sublevel; valence electrons are counted in the last shell.
More board questions on this topic
- Look at these statements:
- How many subshells are there in the N shell of an atom?
- At most how many electrons can the 'K' level hold?
- At most how many electrons can the "M" level hold?
Your account is open, so all 30,000+ MCQs from every chapter are yours. Start practising SSC Chemistry →
Want to keep going?
A free account carries you on to the next questions and opens 30,000+ MCQs from every chapter. Join before launch and Chirkut bundles are 60% off.
The ones you missed, worth one more look