Understanding the Concepts

* Avogadro's Law: Equal volumes of gases at the same temperature and pressure contain the same number of molecules.

* Molecular Composition: Nitrous oxide (N₂O) has 3 atoms per molecule (2 nitrogen + 1 oxygen), while neon (Ne) is a monatomic gas (1 atom per atom).

Steps

1. Equal Number of Molecules: Since we want the same number of *atoms*, we need to find the volume of nitrous oxide that has the same number of *molecules* as 9.00 L of neon. According to Avogadro's Law, this means the volumes will be equal.

2. Accounting for Atoms per Molecule: Nitrous oxide has 3 atoms per molecule, while neon has 1 atom per atom. Therefore, we need 3 times the volume of nitrous oxide to have the same number of atoms as 9.00 L of neon.

Calculation

* Volume of nitrous oxide = 3 * Volume of neon

* Volume of nitrous oxide = 3 * 9.00 L

* Volume of nitrous oxide = 27.0 L

Answer: You would need 27.0 L of nitrous oxide gas to have the same number of atoms as 9.00 L of neon gas at the same temperature and pressure.