Valence Electrons Lewis Structure (Show Lone Pair Electrons) NaBr NCI, CF4 14. 1 Point Each. Identify The Number Of Electrons In The Following Element
The Correct Answer and Explanation is :
Valence Electrons and Lewis Structures of NaBr, NCl, and CF4
1. NaBr (Sodium Bromide)
- Valence Electrons:
- Sodium (Na) is in Group 1 of the periodic table, so it has 1 valence electron.
- Bromine (Br) is in Group 17, so it has 7 valence electrons.
- Lewis Structure of NaBr: Sodium, being a metal, loses its single valence electron to become a Na+ ion. Bromine, a non-metal, accepts the electron to become a Br- ion. The electron transfer results in the formation of Na+ and Br- ions, each with a full octet configuration. In the Lewis structure, this is represented as: Na+ [Br-] where Na+ has no valence electrons (shown as empty), and Br- has a full octet of 8 valence electrons with 3 lone pairs represented as dots around the Br atom.
2. NCl (Nitrogen Monochloride)
- Valence Electrons:
- Nitrogen (N) is in Group 15, so it has 5 valence electrons.
- Chlorine (Cl) is in Group 17, so it has 7 valence electrons.
- Lewis Structure of NCl: Nitrogen and chlorine share one electron to form a covalent bond, where nitrogen completes its octet by sharing electrons. In the Lewis structure: :Cl-N:, where chlorine has 3 lone pairs of electrons (7 valence electrons) and nitrogen has 2 lone pairs and 1 shared pair with chlorine. The shared pair forms the bond.
3. CF4 (Carbon Tetrafluoride)
- Valence Electrons:
- Carbon (C) is in Group 14, so it has 4 valence electrons.
- Fluorine (F) is in Group 17, so each fluorine has 7 valence electrons.
- Lewis Structure of CF4: Carbon shares one electron with each of the four fluorine atoms to form a covalent bond, completing the octet of each fluorine atom and the carbon atom. The structure would be: F: C :F ** | | ** F: C :F ** | | ** F: C :F Each fluorine has 3 lone pairs, and carbon has no lone pairs, as all its valence electrons are involved in bonding.
Explanation:
The valence electrons of an atom are the outermost electrons in its electron cloud. The number of valence electrons determines how an atom bonds with others. In ionic bonds (like NaBr), electrons are transferred. In covalent bonds (like NCl and CF4), electrons are shared between atoms to complete their octets. The lone pair electrons are those that are not shared or involved in bonding, often indicated as dots in a Lewis structure.