How many valence electrons does an atom with five total electrons have?

• A. 5.
• B. 7.
• C. 3.
• D. 2.
• E. 1.

Answer: (C)

Verified step by step guidance

1. Identify the atomic number of the element, which is equal to the number of protons and, in a neutral atom, also the number of electrons. In this case, the atom has five total electrons.
2. Determine the electron configuration of the atom. For an atom with five electrons, the configuration is 1s² 2s² 2p¹.
3. Understand that valence electrons are the electrons in the outermost shell of an atom. For this atom, the outermost shell is the second shell (2s² 2p¹).
4. Count the electrons in the outermost shell. In this case, there are two electrons in the 2s subshell and one electron in the 2p subshell, totaling three valence electrons.
5. Conclude that the atom with five total electrons has three valence electrons, as these are the electrons available for bonding in the outermost shell.