What is the total number of valence electrons in the Lewis structure of S03?
The correct answer and explanation is :
To determine the total number of valence electrons in the Lewis structure of sulfur trioxide (SO₃), we need to consider the valence electrons of each atom in the molecule.
- Identify the atoms in SO₃:
- Sulfur (S) is the central atom.
- Oxygen (O) atoms are attached to the sulfur atom.
- Determine the number of valence electrons for each atom:
- Sulfur is in Group 16 of the periodic table, so it has 6 valence electrons.
- Oxygen is also in Group 16, so each oxygen atom has 6 valence electrons.
- Count the total number of valence electrons:
- There is one sulfur atom and three oxygen atoms in SO₃.
- Sulfur contributes 6 valence electrons, and each of the three oxygen atoms contributes 6 valence electrons.
- Total valence electrons = (6 from sulfur) + (3 × 6 from oxygen) = 6 + 18 = 24 valence electrons.
Thus, the total number of valence electrons in the Lewis structure of SO₃ is 24.
Explanation:
In the Lewis structure of SO₃, we use these 24 valence electrons to form bonds between the atoms. Sulfur, as the central atom, forms double bonds with each of the three oxygen atoms. Each double bond consists of 4 electrons (2 electrons per bond), so three double bonds will use up 12 electrons (3 × 4 = 12 electrons). This leaves 12 electrons remaining.
The remaining 12 electrons are placed as lone pairs on the oxygen atoms. Since there are three oxygen atoms and each oxygen will have two lone pairs, this uses up the remaining 12 electrons (3 × 4 = 12 electrons). This structure satisfies the octet rule for each oxygen atom, and sulfur, being in the third period of the periodic table, can expand its valence shell to accommodate more than 8 electrons.
Thus, the total number of valence electrons used in the structure equals 24, which is the correct number for the Lewis structure of SO₃.