Multiple Choice
In an atom, which type of electron is primarily available to form chemical bonds?
21
views
9. Electrons in Atoms and the Periodic Table
Valence Electrons of Elements (Simplified)
Multiple Choice
Which of the following elements has only one valence electron (based on its main-group position in the periodic table)?
A
Aluminum (Al)
B
Sodium (Na)
C
Chlorine (Cl)
D
Magnesium (Mg)
Verified step by step guidance1
Recall that the number of valence electrons for main-group elements corresponds to the group number in the periodic table. For example, elements in Group 1 have 1 valence electron, Group 2 have 2 valence electrons, and so on.
Identify the group number for each element: Sodium (Na) is in Group 1, Aluminum (Al) is in Group 13, Chlorine (Cl) is in Group 17, and Magnesium (Mg) is in Group 2.
Use the group number to determine the number of valence electrons: Sodium (Na) has 1 valence electron, Aluminum (Al) has 3 valence electrons, Chlorine (Cl) has 7 valence electrons, and Magnesium (Mg) has 2 valence electrons.
Compare the valence electrons of each element to find which one has only one valence electron.
Conclude that the element with only one valence electron is the one in Group 1, which is Sodium (Na).
Related Videos
Related Practice
