To find the electron configuration for boron, we need to understand how electrons are distributed among the orbitals of an atom according to the Aufbau principle, the Pauli exclusion principle, and Hund's rule. Boron has an atomic number of 5, which means it has 5 electrons.
Here's the step-by-step approach to determining the electron configuration for boron:
1. 1s Orbital: The first two electrons will fill the 1s orbital as it is the lowest energy level.
[tex]\[
1s^2
\][/tex]
2. 2s Orbital: The next two electrons will fill the 2s orbital.
[tex]\[
1s^2 2s^2
\][/tex]
3. 2p Orbital: The remaining one electron will go into the 2p orbital as it is the next available energy level.
[tex]\[
1s^2 2s^2 2p^1
\][/tex]
So, the electron configuration for boron is:
[tex]\[
1s^2 2s^2 2p^1
\][/tex]
Now, let's compare this with the given options:
1. [tex]\(1s^2 2s^3\)[/tex] - This configuration is incorrect because an s orbital can hold a maximum of 2 electrons, not 3.
2. [tex]\(1s^2 2s^2 3s^1\)[/tex] - This configuration is incorrect because the 3s orbital should not be filled before the 2p orbital.
3. [tex]\(1s^1 2s^2 2p^2\)[/tex] - This configuration is incorrect because it places 1 electron in the 1s orbital and 2 electrons in the 2p orbital, which does not correspond to the correct filling order.
4. [tex]\(1s^2 2s^2 2p^1\)[/tex] - This configuration is correct as it properly follows the order of filling orbitals and sums up to a total of 5 electrons.
Therefore, the correct electron configuration for boron is:
[tex]\[
1s^2 2s^2 2p^1
\][/tex]
