Textbook Question
What is the group number and number of valence electrons for each of the following elements?e. barium
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9. Electrons in Atoms and the Periodic Table
Valence Electrons of Elements (Simplified)
Multiple Choice
How many valence electrons does an oxygen atom have?
A
8
B
2
C
6
D
4
Verified step by step guidance1
Identify the atomic number of oxygen, which is 8. This means an oxygen atom has 8 protons and, in a neutral atom, 8 electrons.
Recall that electrons are arranged in energy levels or shells around the nucleus. The first shell can hold up to 2 electrons, and the second shell can hold up to 8 electrons.
Determine the electron configuration of oxygen: the first shell is filled with 2 electrons, and the remaining electrons go into the second shell.
Recognize that valence electrons are the electrons in the outermost shell. For oxygen, the outermost shell is the second shell.
Count the number of electrons in the outermost shell (second shell) to find the number of valence electrons. For oxygen, this number is 6.
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