How many valence electrons do the atoms in Group 13 have
The Correct Answer and Explanation is:
The atoms in Group 13 of the periodic table, which includes elements like boron (B), aluminum (Al), and gallium (Ga), each have 3 valence electrons. This is due to their position in the periodic table, specifically the fact that they are in the p-block of the periodic table.
Explanation:
Valence electrons are the electrons in an atom’s outermost shell and are crucial because they participate in chemical bonding. The number of valence electrons an element has depends on its group number in the periodic table. For main group elements, the group number corresponds to the number of valence electrons.
Group 13 elements, also known as the boron group, have the following electron configurations in their outermost shells:
- Boron (B): The electron configuration is 1s22s22p11s^2 2s^2 2p^11s22s22p1. The outermost shell (n=2) contains 3 electrons in the 2s and 2p orbitals, which makes boron have 3 valence electrons.
- Aluminum (Al): The electron configuration is 1s22s22p63s23p11s^2 2s^2 2p^6 3s^2 3p^11s22s22p63s23p1. The outermost shell (n=3) has 3 electrons in the 3s and 3p orbitals, meaning aluminum also has 3 valence electrons.
- Gallium (Ga): The electron configuration is 1s22s22p63s23p64s23d104p11s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^11s22s22p63s23p64s23d104p1. The outermost shell (n=4) holds 3 electrons in the 4s and 4p orbitals, giving gallium 3 valence electrons.
This pattern is consistent across the Group 13 elements. The three valence electrons make these elements prone to losing electrons in chemical reactions, often forming +3 cations (such as Al3+Al^{3+}Al3+ or B3+B^{3+}B3+) when they react with other elements.
