Here's why:

* Molecular formula: This formula represents the actual number of atoms of each element present in a molecule. Methane has one carbon atom and four hydrogen atoms, so CH₄ accurately reflects its composition.

* Empirical formula: This formula shows the simplest whole-number ratio of atoms in a compound. In methane, the ratio of carbon to hydrogen is 1:4, which is already the simplest whole-number ratio. Therefore, CH₄ is also the empirical formula.

In cases where a molecule has multiple units of the same empirical formula, the molecular formula would be different. For example, the empirical formula for glucose is CH₂O, but its molecular formula is C₆H₁₂O₆. However, for methane, the molecular and empirical formulas coincide.