Question

1. the chemical equation for formation of table salt is shown.

2na + cl₂ → 2nacl
sodium chlorine gas sodium chloride
which statement correctly compares the number of atoms in the reactants and in the products?
multiple - choice options with circular selection buttons follow, with partial text of options visible:

• the number of atoms in each molecule of chlorine gas is equal to the number of atoms in each molecule of sodium.
• the total number of atoms in the sodium chloride molecules is equal to the total number of atoms in each molecule of chlorine gas.
• the total number of atoms in the sodium chloride molecules is equal to the total number of atoms in the sodium and chlorine gas molecules.

Explanation:

To solve this, we analyze the law of conservation of mass in chemical reactions, which states that the total number of atoms of each element is conserved (same in reactants and products).

1. Analyze Reactants:

• Reactants: \( 2\text{Na} + \text{Cl}_2 \)
• Sodium (Na): \( 2 \) atoms (from \( 2\text{Na} \)).
• Chlorine (Cl): \( 2 \) atoms (from \( \text{Cl}_2 \), since \( \text{Cl}_2 \) has \( 2 \) Cl atoms).
• Total atoms in reactants: \( 2 + 2 = 4 \).

1. Analyze Products:

• Product: \( 2\text{NaCl} \)
• Each \( \text{NaCl} \) has \( 1 \) Na and \( 1 \) Cl atom. For \( 2\text{NaCl} \):
• Sodium (Na): \( 2 \times 1 = 2 \) atoms.
• Chlorine (Cl): \( 2 \times 1 = 2 \) atoms.
• Total atoms in products: \( 2 + 2 = 4 \).

1. Evaluate Options:

• First option: Compares atoms in \( \text{Cl}_2 \) and \( \text{Na} \) (not reactant vs. product total). Eliminate.
• Second option: Compares \( \text{NaCl} \) molecules to \( \text{Cl}_2 \) molecules (not atom counts). Eliminate.
• Third option: States total atoms in \( \text{NaCl} \) (products) equals total atoms in \( \text{Na} + \text{Cl}_2 \) (reactants). This matches the conservation of mass (both have \( 4 \) atoms).

Answer:

The total number of atoms in the sodium chloride molecules is equal to the total number of atoms in the sodium and chlorine gas molecules.