--- title: Gases all around: breath and balloons — a lesson of Mova's school · trees and pragmatics description: «Gases all around: breath and balloons», a lesson of the chemistry course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Your breath is full of invisible gases: water vapour, which turns to tiny droplets on the cold glass, and carbon dioxide, which yo --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/) [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/) / Gases all around: breath and balloons # Gases all around: breath and balloons Lesson 20 of the chemistry course of Mova's primary school: 19 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/20-gases-all-around-breath-and-balloons/). - [1](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/1/) — Your breath is full of invisible gases: water vapour, which turns to tiny droplets on the cold glass, and carbon dioxide, which your body makes as it uses food. - [2](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/2/) — In class, a teacher can have you breathe out gently through a straw into clear lime water, and it goes milky: carbon dioxide reacts with it and makes tiny bits of chalk. - [3](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/3/) — Ordinary air has so little carbon dioxide that pumping it in hardly clouds the water. - [4](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/4/) — Gases are made of tiny particles zooming about. - [5](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/5/) — Heat them and they move faster and spread out, which is why a hot-air balloon rises; cool them and they slow down, which is why a car tyre looks softer on a frosty morning. - [6](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/6/) — Helium atoms are so tiny they slip through the rubber skin of a party balloon, so it shrinks in a few days. - [7](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/7/) — Some gases you smell, like rotten eggs, but some, like carbon monoxide from engines, have no smell at all and can kill, which is why homes have carbon monoxide alarms. - [8](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/8/) — Breath contains water vapour, which condenses on a cold mirror; the body makes water when it uses food, and you breathe out about a glass of water a day. - [9](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/9/) — Breath has much more carbon dioxide than ordinary air; carbon dioxide turns lime water milky by making tiny chalk particles, a test scientists use. - [10](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/10/) — Helium atoms are so small they slip through rubber, so helium balloons shrink after a few days; foil balloons last longer because their skin has smaller gaps. - [11](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/11/) — Released balloons come down far away, do not break down quickly and can harm animals that eat them; many places now ban balloon releases. - [12](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/12/) — A hot-air balloon rises because heated air spreads out, so the same space holds less air and is lighter than the cold air outside; the burner keeps the air hot. - [13](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/13/) — The first hot-air balloon passengers, in 1783, were a sheep, a duck and a cockerel. - [14](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/14/) — Rotten eggs smell because bacteria break down proteins with sulphur in them and give off hydrogen sulphide gas; noses can sense tiny amounts of it, and some hot springs smell of it too. - [15](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/15/) — The white cloud from a car exhaust on a cold morning is mostly water vapour; burning petrol also makes carbon dioxide and some harmful gases. - [16](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/16/) — Carbon monoxide has no smell and can kill, so a car must never run in a closed garage and carbon monoxide alarms are useful at home. - [17](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/17/) — A fish-tank pump bubbles air into the water, and some oxygen from the bubbles dissolves for the fish. - [18](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/18/) — Water plants use light to make sugar and give off oxygen, so pondweed makes bubbles in sunlight and stops in the dark. - [19](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/20-gases-all-around-breath-and-balloons/19/) — Cold gas particles move slower and hit the walls less hard, so tyres have lower pressure in cold weather and drivers check them more often in winter. - ← previous: [Fizzy drinks, Mentos and cola](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/19-fizzy-drinks-mentos-and-cola/) - next →: [Bread rising: yeast at work](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/21-bread-rising-yeast-at-work/) - ↑ back to [Chemistry](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/)