Which statement is true about the Lewis Structure for LiBr? the anion has a full outer octet has ” SP3 hybridization it has two single bonds it is trigonal planar lithium has two lone pairs of electrons
The Correct Answer and Explanation is:
The correct answer is: the anion has a full outer octet
Explanation:
To determine the correct statement about the Lewis structure for Lithium Bromide (LiBr), we first need to understand the type of bonding involved. Lithium (Li) is an alkali metal from Group 1 of the periodic table, and Bromine (Br) is a halogen from Group 17. The significant difference in electronegativity between the metal (Li) and the nonmetal (Br) indicates that they form an ionic bond, not a covalent one.
In an ionic bond, electrons are transferred from the metal to the nonmetal. Lithium has one valence electron, which it readily loses to form a stable positive ion, the lithium cation (Li⁺). Bromine has seven valence electrons and needs one more electron to achieve a stable electron configuration. It gains the electron from lithium to form a negative ion, the bromide anion (Br⁻).
The Lewis structure for an ionic compound reflects this transfer of electrons. It shows the resulting ions with their respective charges. The structure for LiBr is written as:
[Li]⁺ [:Br̈:]⁻
Now, let’s evaluate each statement:
- the anion has a full outer octet: The anion in LiBr is the bromide ion (Br⁻). A neutral bromine atom has seven valence electrons. By gaining one electron from lithium, it now has eight valence electrons (a full octet) in its outer shell, which is a very stable configuration. This statement is true.
- it has SP3 hybridization: Hybridization is a concept used to describe the mixing of atomic orbitals to form new hybrid orbitals for covalent bonding. Since LiBr is an ionic compound with no shared electron pairs, the concept of hybridization does not apply. This statement is false.
- it has two single bonds: LiBr forms a single ionic bond, which is the electrostatic attraction between one Li⁺ ion and one Br⁻ ion. It does not form covalent single bonds, and there is certainly not more than one bond in the simple formula unit. This statement is false.
- it is trigonal planar: Trigonal planar describes a molecular geometry, typically for a molecule with a central atom bonded to three other atoms. LiBr is a simple diatomic compound and does not have this complex shape. This statement is false.
- lithium has two lone pairs of electrons: The lithium atom loses its single valence electron to become the Li⁺ cation. The resulting cation has no valence electrons and therefore no lone pairs. This statement is false.
Based on this analysis, the only true statement is that the anion, Br⁻, has a full outer octet.
