--- title: Glass and pottery — a lesson of Mova's school · trees and pragmatics description: «Glass and pottery», a lesson of the chemistry course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A window pane is made of sand. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/) [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/) / Glass and pottery # Glass and pottery Lesson 30 of the chemistry course of Mova's primary school: 17 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/30-glass-and-pottery/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/0/) — A window pane is made of sand. - [1](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/1/) — Sand is melted with soda and crushed limestone in a furnace hotter than 1000 °C, and the glowing runny glass is cooled into sheets, bottles and jars. - [2](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/2/) — When glass cools, its particles do not have time to line up in neat crystals; they freeze in a jumble, so glass is a hard solid that breaks with smooth, razor-sharp edges. - [3](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/3/) — Hot glass is soft like toffee: a glassblower blows into a blob of it on a long pipe and it swells into a bubble that becomes a vase. - [4](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/4/) — Nature makes glass too, when lightning strikes sand or lava cools very fast. - [5](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/5/) — Pottery is different: soft clay is shaped and then baked in a very hot oven called a kiln until it turns hard as stone. - [6](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/6/) — A shiny glaze, which is a thin coat of glass, makes a mug waterproof. - [8](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/8/) — In glass the particles are frozen in a jumble instead of neat crystals; old windows that are thicker at the bottom were made that way, glass does not slowly flow down. - [9](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/9/) — Glassblowers shape glass that is over 1000 °C, when it is soft and stretchy. - [10](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/10/) — Oven glass expands very little when heated, so it does not crack in the oven; ordinary glass can crack when heated or cooled unevenly, for example a hot dish put into cold water. - [11](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/11/) — Lightning striking sand can melt it into glass tubes called fulgurites; volcanoes make a natural black glass called obsidian. - [13](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/13/) — Broken glass splits into thin, sharp edges, so it is swept up carefully with a brush and dustpan, never picked up with bare hands. - [14](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/14/) — Car side and back windows are toughened to crumble into small blunt pieces; the windscreen has a layer of plastic inside, so it cracks but holds together. - [15](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/15/) — Pottery is clay baked in a kiln at a very high heat, which makes it hard for good; a glaze is a thin glass coating that makes it waterproof; a clay pot must dry out fully before firing, or the water inside turns to steam and can crack it. - [16](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/16/) — Glass can be melted and made into new bottles again and again without wearing out, and melting old glass needs less energy than making it from sand. - [17](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/17/) — Phone screens are toughened glass, treated so the surface is harder; a drop on a corner can still crack them. - [18](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/30-glass-and-pottery/18/) — Optical fibres are thin strands of glass that carry light along bends, because the light keeps bouncing inside the fibre; most of the internet travels through such fibres, even under the oceans. - ← previous: [Plastics: useful and stubborn](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/29-plastics-useful-stubborn/) - next →: [Metals and what they're good for](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/31-metals-what-theyre-good-for/) - ↑ back to [Chemistry](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/)