Question

electrons an atom needs to satisfy the octet rule. atoms may form single, double, or triple bonds. electron dot structures also show lone pairs of electrons.
solve apply the concepts to this problem.
draw the electron dot structures for the atoms.
determine how many electrons each atom needs.
identify the central atom for molecules with more than two atoms. it must be able to form more than one single bond.
draw the electron dot structure of the molecule so that each atom, except hydrogen, has an octet.
check that the total number of electrons in the structure is the same as the sum of the valence electrons in the atoms.
15 draw the electron dot structures for the molecular compounds.
a. bri
b. ch₄

Explanation:

Step1: Determine valence electrons

• For \( \text{BrI} \):
• Bromine (\( \text{Br} \)) has \( 7 \) valence electrons.
• Iodine (\( \text{I} \)) has \( 7 \) valence electrons.
• Total valence electrons \(=7 + 7=14\).
• For \( \text{CH}_4 \):
• Carbon (\( \text{C} \)) has \( 4 \) valence electrons.
• Each hydrogen (\( \text{H} \)) has \( 1 \) valence electron.
• Total valence electrons \(=4+(4\times1)=8\).

Step2: Draw electron - dot structures

• For \( \text{BrI} \):
• Since it is a diatomic molecule (two atoms), they share one pair of electrons to form a single bond.
• The structure is \( :\text{Br}:\text{I}: \).
• For \( \text{CH}_4 \):
• Carbon is the central atom.
• Carbon forms four single bonds with four hydrogen atoms.
• The structure is \( \text{H}:\text{C}:\text{H} \) with each \( \text{H} \) on the four sides of \( \text{C} \) (in a tetrahedral electron - dot representation, we can show it as \( \text{H}\underset{\text{H}}{\overset{\text{H}}{\text{C}}}\text{H} \) in dot structure terms, where each line represents a pair of shared electrons).

Answer:

a. \( :\text{Br}:\text{I}: \)
b. \( \text{H}\underset{\text{H}}{\overset{\text{H}}{\text{C}}}\text{H} \) (where each line between \( \text{C} \) and \( \text{H} \) represents a pair of shared electrons in the electron - dot structure sense)