Composition of the Atmosphere extended definition. 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.
(CNN)Iran has completed the necessary steps in a deal to restrict its nuclear program, meaning international economic sanctions are lifted, officials from the EU and the U.N. nuclear watchdog agency said Saturday. Relations between Iran and the IAEA now enter a new phase.
Itâs a common belief that Iran holds the same status as Cuba for American citizens (i.e., that itâs illegal to visit without special permission from the U.S. government). Although the United States has imposed sanctions against Iran, there are currently no restrictions on American citizens visiting Iran as tourists.