--- title: Plastics: useful and stubborn — a lesson of Mova's school · trees and pragmatics description: «Plastics: useful and stubborn», a lesson of the chemistry course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Look round your kitchen: a water bottle, a lunchbox, a toy brick, the handle of a toothbrush. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Chemistry](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/) / Plastics: useful and stubborn # Plastics: useful and stubborn Lesson 29 of the chemistry course of Mova's primary school: 18 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/chemistry/29-plastics-useful-stubborn/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/0/) — Look round your kitchen: a water bottle, a lunchbox, a toy brick, the handle of a toothbrush. - [1](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/1/) — They feel different, but all are plastics, made of very long chain molecules called polymers, like thousands of paperclips clipped into one chain. - [2](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/2/) — Long chains make plastics bendy, tough and light. - [3](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/3/) — Pull a plastic bag slowly and it thins and stretches before it tears, because the chains slide past each other and line up. - [4](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/4/) — Plastics are useful everywhere, from hospitals to raincoats, but they are stubborn: they last for hundreds of years, and in the sea they break into tiny bits instead of disappearing. - [5](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/5/) — Most plastics are made from oil, but nature has its own chains too: rubber comes from the sap of rubber trees, and some new plastics are made from corn or sugar cane. - [6](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/6/) — Plastics are polymers: very long chain molecules made by linking many small molecules together. - [7](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/7/) — Most plastics are made from oil and natural gas. - [8](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/8/) — When a plastic bag is stretched, its long chains slide past each other and line up, so it thins out before it tears. - [9](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/9/) — The number inside a little triangle of arrows on a plastic item tells which kind of plastic it is; it helps sorting, but not every kind is recycled everywhere. - [10](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/10/) — Plastic lasts hundreds of years and slowly breaks into tiny pieces called microplastics, because few microbes can eat it. - [12](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/12/) — Rubber is a natural polymer from the sap of rubber trees; its chains are joined by links that pull it back into shape after stretching. - [13](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/13/) — Many plastics soften when heated, because heat lets the chains move; burning plastic gives off poisonous fumes. - [14](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/14/) — The non-stick coating on frying pans is a slippery plastic that food cannot grip; it was discovered by accident in 1938. - [15](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/15/) — Some new plastics are made from plants such as corn or sugar cane; some of these can be composted, but only in special hot composters. - [16](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/16/) — Nylon was invented in the 1930s to replace silk; it was cheaper and stronger, so people queued for hours for the first nylon stockings; it is used in coats, ropes and toothbrush bristles. - [17](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/17/) — In hospitals, sealed plastic syringes, gloves and tubes keep medicine and tools free of germs and are used only once. - [18](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/18/) — Plastic itself is very useful; the big problem is plastic thrown away where it does not belong. - ← previous: [Leaves, fruit and colour in nature](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/28-colour-in-nature/) - next →: [Glass and pottery](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/) - ↑ back to [Chemistry](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/)