Electron Configuration Practice
8 problems · instant feedback · full explanations
Electron configurations explain the periodic table's shape and how atoms bond. These eight problems cover writing configurations, valence electrons, and ions, with the reasoning shown for each.
Q1.
The electron configuration of oxygen (Z = 8) is:
Multiple choice · Easy
Q2.
How many valence electrons does chlorine (Z = 17) have?
Multiple choice · Easy
Q3.
The 4s subshell fills before the 3d subshell.
True / False · Medium
Q4.
A sodium atom loses one electron to form Na+. Its electron configuration becomes:
Multiple choice · Medium
Q5.
What is the maximum number of electrons a d subshell can hold?
Numerical answer · Easy
Q6.
Which element has the electron configuration 1s2 2s2 2p6 3s2 3p6?
Multiple choice · Medium
Q7.
A single orbital can hold at most two electrons.
True / False · Beginner
Q8.
How many valence electrons does carbon have?
Multiple choice · Easy