Multiple Choice
How many valence electrons does an atom of aluminum (Al) have?
3
views
10. Periodic Properties of the Elements
Valence Electrons of Elements
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
How many unpaired electrons are present in a sulfur (S) atom in its ground state?
A
2
B
6
C
4
D
0
Verified step by step guidance1
Identify the atomic number of sulfur (S), which is 16. This means a neutral sulfur atom has 16 electrons.
Write the electron configuration of sulfur in its ground state. The order of filling orbitals is: 1s, 2s, 2p, 3s, 3p. So, sulfur's electron configuration is $1s^2 2s^2 2p^6 3s^2 3p^4$.
Focus on the outermost electrons, which are in the 3p subshell with 4 electrons. The 3p subshell has three orbitals, each can hold up to 2 electrons.
Apply Hund's rule to distribute the 4 electrons in the three 3p orbitals: place one electron in each orbital first (all unpaired), then pair the fourth electron in one of the orbitals.
Count the number of unpaired electrons after distribution. Since one orbital has two electrons paired, and the other two orbitals have one electron each, the number of unpaired electrons is 2.
2:32mWatch next
Master Main Group Elements Valence Electrons with a bite sized video explanation from Jules
Start learningRelated Videos
Related Practice
Valence Electrons of Elements practice set
Problem sets built by lead tutorsExpert video explanations