Final answer:
To determine the number of electrons in a molecule's Lewis structure, sum the valence electrons of each atom; for ions, adjust for the charge. The correct option is (d), the sum of the valence electrons of each atom in the molecule.
Step-by-step explanation:
To determine the number of electrons in the Lewis structure of a molecule, one follows a specific procedure. The correct answer to the question is (d): The total number of electrons for a Lewis structure of a molecule is the sum of the valence electrons of each atom in the molecule. Here's how you can find this total:
- Add together the valence electrons from each atom in the molecule, which are indicated by the position of the element on the periodic table.
- If dealing with a polyatomic ion, adjust the total number of electrons by adding for a negative charge or subtracting for a positive charge to match the overall charge of the ion.
- These electrons will be arranged as bonding pairs between atoms and, if necessary, as lone pairs around atoms to complete their octets or duets (in the case of hydrogen).
It's important to note that this count of valence electrons includes only those found in the outermost shell, and not electrons in the d or f orbitals.