1. Atomic Number: Bromine (Br) has an atomic number of 35, meaning it has 35 protons and 35 electrons.
2. Electronic Configuration: To write the electronic configuration, we follow the Aufbau principle and Hund's rule:
* Aufbau Principle: Electrons fill orbitals in order of increasing energy.
* Hund's Rule: Within a subshell, electrons will individually occupy each orbital before doubling up in any one orbital.
3. Orbital Filling Order:
* 1s² (2 electrons)
* 2s² (2 electrons)
* 2p⁶ (6 electrons)
* 3s² (2 electrons)
* 3p⁶ (6 electrons)
* 4s² (2 electrons)
* 3d¹⁰ (10 electrons)
* 4p⁵ (5 electrons)
4. Complete Ground State Configuration:
The ground state electronic configuration of bromine is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁵
Important Note: This configuration is often written in a shorthand form using the previous noble gas as a starting point:
[Ar] 4s² 3d¹⁰ 4p⁵ (where [Ar] represents the configuration of argon, the noble gas preceding bromine).
