Multiple Choice
Which of the following is the correct electron configuration for argon (atomic number 18)?
76
views
10. Periodic Properties of the Elements
The Electron Configuration
Multiple Choice
Which of the following is the correct electron configuration for fluorine (atomic number 9)?
A
1s^2 2s^2 2p^4
B
1s^2 2s^2 2p^5
C
1s^2 2s^2 2p^6
D
1s^2 2s^2 2p^3
Verified step by step guidance1
Step 1: Identify the atomic number of fluorine, which is 9. This means fluorine has 9 electrons to be placed in atomic orbitals according to the Aufbau principle.
Step 2: Recall the order of filling orbitals: 1s, 2s, then 2p. The 1s orbital can hold up to 2 electrons, so fill 1s with 2 electrons: \$1s^{2}$.
Step 3: Next, fill the 2s orbital, which can also hold 2 electrons: \$2s^{2}$. Now, 4 electrons have been placed (2 in 1s and 2 in 2s).
Step 4: The remaining electrons (9 total - 4 placed = 5 electrons) go into the 2p orbitals. Since 2p can hold up to 6 electrons, place 5 electrons as \$2p^{5}$.
Step 5: Combine all parts to write the full electron configuration for fluorine: \$1s^{2} 2s^{2} 2p^{5}$. This matches the correct electron configuration.
Related Videos
Related Practice
