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Multiple Choice
How many valence electrons does an atom of aluminum (Al) possess?
A
5
B
1
C
8
D
3
Verified step by step guidance
1
Identify the atomic number of aluminum (Al), which is 13, meaning it has 13 electrons in total.
Determine the electron configuration of aluminum to understand the distribution of electrons in its shells. The configuration is $1s^2 2s^2 2p^6 3s^2 3p^1$.
Recognize that valence electrons are the electrons in the outermost shell (highest principal quantum number). For aluminum, this is the third shell (n=3).
Count the electrons in the outermost shell: $3s^2$ and $3p^1$ add up to 3 valence electrons.
Conclude that aluminum has 3 valence electrons based on its electron configuration and the definition of valence electrons.