Multiple Choice
How many valence electrons does a bromine (Br) atom have?
9. Electrons in Atoms and the Periodic Table
Valence Electrons of Elements (Simplified)
Multiple Choice
How many valence electrons does a calcium (Ca) atom have?
A
6
B
2
C
1
D
8
Verified step by step guidance1
Identify the element in question, which is calcium (Ca).
Recall that valence electrons are the electrons in the outermost shell of an atom.
Determine the electron configuration of calcium. Calcium has an atomic number of 20, so it has 20 electrons.
Write the electron configuration for calcium: \$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2$.
Identify the electrons in the outermost shell, which is the 4th shell (4s orbital), and count them. These are the valence electrons.
Related Videos
Related Practice
