Natural gas in its native state is colorless and odorless. Mercaptan is the additive that is added to natural gas to make it easier to detect in case of a leak.
Hydrogen gas density is 0.08988 kg/m3 under STP (0°C, 1 atm), so the volume is
V=m / ρ = 18,000 / 0.08988 = 2.002 × 105 (m3).
Overdriving your headlights<span> means not being able to stop inside the illuminated area ahead. It is difficult to judge other vehicles' speeds and distances at night. </span>Do<span> not</span>overdrive your headlights<span>—it creates a blind "crash area" in front of </span>your<span> vehicle. </span>You should<span> be able to stop inside the illuminated area ahead.</span>
