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Which of the following best describes valence electrons and explains their importance in chemistry?
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10. Periodic Properties of the Elements
Valence Electrons of Elements
Multiple Choice
How many valence electrons does a neutral atom of oxygen have?
A
6
B
4
C
2
D
8
검증된 단계별 안내1
Identify the element in question, which is oxygen. Oxygen has an atomic number of 8, meaning it has 8 protons and, in a neutral atom, 8 electrons.
Recall that valence electrons are the electrons in the outermost shell (energy level) of an atom that participate in chemical bonding.
Determine the electron configuration of oxygen to find how the 8 electrons are distributed among the shells. The configuration is 1s\^2 2s\^2 2p\^4.
Recognize that the first shell (1s) holds 2 electrons and is full, so the valence electrons are those in the second shell (2s and 2p orbitals).
Add the electrons in the 2s and 2p orbitals: 2 (from 2s) + 4 (from 2p) = 6 valence electrons for a neutral oxygen atom.
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