1. Electronic Configuration:
* Iodine (I) has an atomic number of 53, meaning it has 53 electrons.
* The electronic configuration of iodine is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁵
2. Core Electrons:
* Core electrons are the electrons in the inner shells of an atom. They are not involved in chemical bonding.
* In the electronic configuration, all the electrons in shells below the outermost (valence) shell are core electrons.
* In iodine, the outermost shell is the 5th shell (5p⁵).
3. Counting Core Electrons:
* Count the electrons in shells 1, 2, 3, and 4:
* 1s² (2 electrons)
* 2s² 2p⁶ (8 electrons)
* 3s² 3p⁶ 3d¹⁰ (18 electrons)
* 4s² 4p⁶ 4d¹⁰ (18 electrons)
4. Total Core Electrons: 2 + 8 + 18 + 18 = 46 core electrons
Therefore, an iodine atom has 46 core electrons.
