Multiple Choice
How many valence electrons does the element krypton (Kr) 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 valence electrons are present in a neutral atom of aluminum (Al)?
A
2
B
3
C
1
D
5
Verified step by step guidance1
Identify the atomic number of aluminum (Al), which is 13. This means a neutral aluminum atom has 13 electrons.
Determine the electron configuration of aluminum by filling the orbitals in order: 1s, 2s, 2p, 3s, and 3p.
Write the electron configuration for aluminum: $1s^2 2s^2 2p^6 3s^2 3p^1$.
Recognize that valence electrons are the electrons in the outermost shell (highest principal quantum number). For aluminum, this is the third shell (3s and 3p orbitals).
Count the electrons in the 3s and 3p orbitals: $3s^2$ and $3p^1$, which totals 3 valence electrons.
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