Plastic is a word that originally meant “pliable and easily shaped.” It only recently became a name for a category of materials called polymers. The word polymer means “of many parts,” and polymers are made of long chains of molecules. Polymers abound in nature. Cellulose, the material that makes up the cell walls of plants, is a very common natural polymer.
Over the last century and a half humans have learned how to make synthetic polymers, sometimes using natural substances like cellulose, but more often using the plentiful carbon atoms provided by petroleum and other fossil fuels. Synthetic polymers are made up of long chains of atoms, arranged in repeating units, often much longer than those found in nature. It is the length of these chains, and the patterns in which they are arrayed, that make polymers strong, lightweight, and flexible. In other words, it’s what makes them so plastic.
These properties make synthetic polymers exceptionally useful, and since we learned how to create and manipulate them, polymers have become an essential part of our lives. Especially over the last 50 years plastics have saturated our world and changed the way that we live.
The First Synthetic Plastic
The first synthetic polymer was invented in 1869 by John Wesley Hyatt, who was inspired by a New York firm’s offer of $10,000 for anyone who could provide a substitute for ivory. The growing popularity of billiards had put a strain on the supply of natural ivory, obtained through the slaughter of wild elephants. By treating cellulose, derived from cotton fiber, with camphor, Hyatt discovered a plastic that could be crafted into a variety of shapes and made to imitate natural substances like tortoiseshell, horn, linen, and ivory.
This discovery was revolutionary. For the first time human manufacturing was not constrained by the limits of nature. Nature only supplied so much wood, metal, stone, bone, tusk, and horn. But now humans could create new materials. This development helped not only people but also the environment. Advertisements praised celluloid as the savior of the elephant and the tortoise. Plastics could protect the natural world from the destructive forces of human need.
The creation of new materials also helped free people from the social and economic constraints imposed by the scarcity of natural resources. Inexpensive celluloid made material wealth more widespread and obtainable.
The colonist were unhappy because they were passed in Englade but not in their own colonial governments.
Answer:
Explanation:
The presidents you want to look into are
1. George Washington who refused to serve a third term thus setting the precedent of not serving more than 2 terms.
2. Theodore Roosevelt who wrestled with the prospect of a third term and then decided against doing and then wished he had (run for the 3rd term). He did try again after Taft served one term. Teddy ran under the Bullmoose banner as an independent. He was defeated by Woodrow Wilson who got 41% of the popular vote to Roosevelt's 27%.
3. Franklin Roosevelt who actually did run for 4 terms although he died in office in 1944. He was one of the great presidents of the 20th century and ranks highly among all presidents for what he accomplished.
In 1951, the 22nd Amendment was passed limiting the president's terms in office at 2.
What do you mean by 16 and 17????????
