To become an operative part of the Constitution, an amendment, whether proposed by Congress or a national constitutional convention, must be ratified by either: 1  The legislatures of three-fourths (at present 38) of the states; or. 2  State ratifying conventions in three-fourths (at present 38) of the states.
But more of that in a second. The Earthâs atmosphere is composed of the following molecules: nitrogen (78%), oxygen (21%), argon (1%), and then trace amounts of carbon dioxide, neon, helium, methane, krypton, hydrogen, nitrous oxide, xenon, ozone, iodine, carbon monoxide, and ammonia.
An atmosphere is more likely to be retained if the gravity is high and the atmosphere's temperature is low. The atmosphere of Earth is mostly composed of nitrogen. It also contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis.