To determine which of the given compounds has an atom with more than eight valence electrons, let's consider the valence electron configurations for each compound.
1. HBr (Hydrogen Bromide)
- Bromine (Br) is in Group 17 of the periodic table and has 7 valence electrons.
- In HBr, Bromine typically follows the octet rule and does not exceed eight valence electrons.
2. [tex]\(H_2O\)[/tex] (Water)
- Oxygen (O) is in Group 16 and has 6 valence electrons.
- In [tex]\(H_2O\)[/tex], Oxygen follows the octet rule, gaining 2 electrons from the two hydrogen atoms, reaching exactly eight valence electrons.
3. [tex]\(H_2SO_4\)[/tex] (Sulfuric Acid)
- Sulfur (S) is in Group 16 and has 6 valence electrons.
- However, Sulfur is in the third period of the periodic table, which means it can have an expanded octet. This is because elements in the third period and below have d-orbitals available for bonding.
- In [tex]\(H_2SO_4\)[/tex], Sulfur can indeed have more than eight valence electrons. Specifically, it can accommodate additional electrons by utilizing its 3d orbitals.
4. [tex]\(H_2CO_3\)[/tex] (Carbonic Acid)
- Carbon (C) is in Group 14 and has 4 valence electrons.
- In [tex]\(H_2CO_3\)[/tex], Carbon follows the octet rule and gains four more electrons to complete its eight valence electrons.
Given the above considerations, Sulfur in [tex]\(H_2SO_4\)[/tex] can have more than eight valence electrons due to its ability to expand its octet using the 3d orbitals. Therefore, the compound with an atom that has more than eight valence electrons is:
(C) [tex]\(H_2SO_4\)[/tex]
