An exoplanet probe is designed to measure the concentration of ch4(g) in the atmosphere of an extrasolar planet. the acceleration of gravity on this planet at the elevation of interest is 45 m s-2 and the atmospheric temperature in the region of interest is 348 k. fill the blank: the natural variation in ch4(g) concentration over a 1-kilometer vertical distance due to the change in gravitational potential energy is % km-1

note: required precision is 1% sanity check: the answer is a percentage so the value should be between 1 and 99.