Question

Element with electronic configuration \( 1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 4d^{10} 5s^2 5p^3 \) belongs to the following group of the periodic table:

• A. 5th
• B. 15th
• C. 3rd
• D. 17th

Hint:

For determining the group of an element: - Identify the outermost shell and count the valence electrons. - For p-block elements, the group number = number of valence electrons.

Answer 1

The Correct Option is B

Step 1: Identify the valence electrons in the given electronic configuration. The electronic configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 4d^{10} 5s^2 5p^3. \] The outermost shell is the 5th shell, and the valence electrons are in the \( 5s^2 \) and \( 5p^3 \) orbitals. 
Step 2: Calculate the total number of valence electrons. - Electrons in \( 5s^2 \): 2 - Electrons in \( 5p^3 \): 3 Total valence electrons = \( 2 + 3 = 5 \).
Step 3: Determine the group number. The number of valence electrons corresponds to the group number in the periodic table for the p-block elements. Since the element has 5 valence electrons, it belongs to Group 15. 
Conclusion: The element belongs to the 15th group of the periodic table.