How many valence electrons does an atom of a group 15 element have in the periodic table?

• A. 3
• B. 7
• C. 5
• D. 8

Answer: (C)

Verified step by step guidance

1. Identify the group number of the element in the periodic table. Group 15 elements are located in the p-block and are also known as the nitrogen group.
2. Recall that the group number for main group elements corresponds to the total number of valence electrons. For groups 13 to 18, the number of valence electrons is given by subtracting 10 from the group number (e.g., group 15 - 10 = 5).
3. Understand that valence electrons include both the s and p electrons in the outermost shell. For group 15, the valence shell configuration is typically ns\u00b2 np\u00b3, which sums to 5 electrons.
4. Confirm that the valence electron count for group 15 elements is 5 by considering the electron configuration of a representative element, such as nitrogen (1s\u00b2 2s\u00b2 2p\u00b3).
5. Conclude that an atom of a group 15 element has 5 valence electrons.