Density is mass divided by volume in consistent units

Steps:

• Convert mass from grams to kilograms: 4.8 g = 0.0048 kg.
• Use volume as given: 1.2 m³.
• Calculate density: ρ = mass / volume = 0.0048 kg / 1.2 m³ = 0.004 kg m⁻³.
• Express in scientific notation: 0.004 = 4.0 × 10⁻³ kg m⁻³.

Why A is correct:

• Matches the density formula ρ = m/V using SI units (kg and m³), yielding 4.0 × 10⁻³ kg m⁻³ for a low-density gas.

Why the others are wrong:

• B: Ten times too high; error in decimal placement during division.
• C: A million times too high; confuses gas with solid/liquid densities like water (10³ kg m⁻³).
• D: A hundred thousand times too high; similar unit mismatch as C but less extreme.

Final answer: A