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.
Composition of the Atmosphere. The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.