Compounds that have the same molecular formula but different chemical structures are called isomers. Remember isomerism is a property between a pair (or more) of molecules, i.e. a molecule is an isomer of another molecule. A similar relationship is that of brother or sister...
Many Americans are up in arms. But in fact, keeping out desperate souls seeking entry into America has deep roots. On this day 100 years ago, the United States passed the strictest immigration law of its time: the Immigration Act of 1917. The law restricted the immigration of undesirables, including many people from the Middle East and Asia, through increased taxes, tests and outright bans.
Immigration Archives - A Summary of the Immigration Laws of the United States from 1882. Prior to 1882, there were not any formal acts that controlled immigration. Below is a brief summary of the Immigration Acts passed beginning in 1882. By the end of 1954, the transatlantic steamships and ocean liners were almost exclusively for pleasure trips.