Question

for each row in the table below, decide whether the pair of elements will form a molecular compound, check the box and enter the chemical formula of the compound. (if the elements will form more than one molecular compound, use the compound with the fewest total number of atoms.) you may assume all chemical bonds are single bonds, not double or triple bonds.

element #1	element #2	element pair will form a molecular compound	molecular compound chemical formula	molecular compound name
oxygen	hydrogen	$square$	$square$	$square$
magnesium	bromine	$square$	$square$	$square$

Explanation:

To solve this, we analyze each element pair:

Row 1: Hydrogen (H) & Chlorine (Cl)

• Molecular Compound? Yes (both nonmetals, form covalent bonds).
• Formula (fewest atoms): $HCl$ (1 H, 1 Cl; total atoms = 2).
• Name: Hydrogen chloride (or hydrochloric acid, but as a molecular compound, "hydrogen chloride" is precise).

Row 2: Oxygen (O) & Hydrogen (H)

• Molecular Compound? Yes (both nonmetals, form covalent bonds).
• Formula (fewest atoms): $H_2O$ (2 H, 1 O; total atoms = 3).
• Name: Dihydrogen monoxide (or water, but "dihydrogen monoxide" is the systematic name).

Row 3: Magnesium (Mg) & Bromine (Br)

• Molecular Compound? No (Mg is a metal, Br is a nonmetal; they form an ionic compound, not molecular).

Filling the Table:

Element #1	Element #2	Element pair will form a molecular compound?	Molecular compound formula	Molecular compound name
Oxygen	Hydrogen	$\boldsymbol{\checkmark}$	$H_2O$	Dihydrogen monoxide
Magnesium	Bromine	$\boldsymbol{\times}$	–	–

Key Notes:

• Molecular compounds form between nonmetals (covalent bonding).
• Ionic compounds (metal + nonmetal) are not molecular, so we mark "×" for Mg/Br.
• For formulas, use the smallest whole-number ratio (oxidation states: H=+1, Cl=-1; O=-2, H=+1).

Answer:

To solve this, we analyze each element pair:

Row 1: Hydrogen (H) & Chlorine (Cl)

• Molecular Compound? Yes (both nonmetals, form covalent bonds).
• Formula (fewest atoms): $HCl$ (1 H, 1 Cl; total atoms = 2).
• Name: Hydrogen chloride (or hydrochloric acid, but as a molecular compound, "hydrogen chloride" is precise).

Row 2: Oxygen (O) & Hydrogen (H)

• Molecular Compound? Yes (both nonmetals, form covalent bonds).
• Formula (fewest atoms): $H_2O$ (2 H, 1 O; total atoms = 3).
• Name: Dihydrogen monoxide (or water, but "dihydrogen monoxide" is the systematic name).

Row 3: Magnesium (Mg) & Bromine (Br)

• Molecular Compound? No (Mg is a metal, Br is a nonmetal; they form an ionic compound, not molecular).

Filling the Table:

Element #1	Element #2	Element pair will form a molecular compound?	Molecular compound formula	Molecular compound name
Oxygen	Hydrogen	$\boldsymbol{\checkmark}$	$H_2O$	Dihydrogen monoxide
Magnesium	Bromine	$\boldsymbol{\times}$	–	–

Key Notes:

• Molecular compounds form between nonmetals (covalent bonding).
• Ionic compounds (metal + nonmetal) are not molecular, so we mark "×" for Mg/Br.
• For formulas, use the smallest whole-number ratio (oxidation states: H=+1, Cl=-1; O=-2, H=+1).