--- title: Oil and water, and things that won't mix — a lesson of Mova's school · trees and pragmatics description: «Oil and water, and things that won't mix», a lesson of the chemistry course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Pour oil into a glass of water and it sits on top in its own layer, however long you wait. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/) [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/) / Oil and water, and things that won't mix # Oil and water, and things that won't mix Lesson 7 of the chemistry course of Mova's primary school: 15 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/7-oil-and-water/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/0/) — Pour oil into a glass of water and it sits on top in its own layer, however long you wait. - [1](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/1/) — Water molecules cling to each other far more than to oil, so they squeeze the oil out, and oil, being lighter for its size, floats. - [2](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/2/) — Shake a bottle of salad dressing and the oil breaks into tiny droplets for a while, but the droplets soon join up again. - [3](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/3/) — Egg yolk can keep the droplets apart for good: its molecules have one end that likes water and one that likes oil, which is how thick, creamy mayonnaise is made. - [4](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/4/) — The same rule explains greasy fingers that water won't clean, ducks that stay dry, and the fat that sets on top of cold soup. - [5](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/5/) — Oil and water do not mix; they form two layers with oil on top, because oil is less dense than water. - [6](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/6/) — Shaking breaks oil into small droplets, but they join up again unless something holds them apart. - [7](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/7/) — Mustard or egg yolk helps oil droplets stay apart longer in a dressing. - [9](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/9/) — A thin film of oil on a puddle shows rainbow colours, as soap bubbles do, because light reflects off its top and bottom; the colours depend on how thick the film is, so they swirl as it spreads and drifts. - [10](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/10/) — Spilled oil floats on the sea and coats birds' feathers, so they cannot keep warm or fly; rescuers wash them with washing-up liquid. - [11](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/11/) — Grease does not dissolve in water; soap links grease and water so it can be rinsed away, and warm water helps. - [12](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/12/) — In a lava lamp, wax heated at the bottom expands, becomes less dense and rises, then cools and sinks. - [14](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/14/) — Density means how much stuff is packed into the same space. - [15](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/15/) — Ducks spread oil from a gland near the tail over their feathers, so water runs off; that is why they preen so much. - [16](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/7-oil-and-water/16/) — Fat from cooled soup rises and sets on top; poured down the sink it hardens in pipes and helps build huge blockages called "fatbergs". - ← previous: [Mixing and dissolving](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/6-mixing-and-dissolving/) - next →: [Separating mixtures](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/8-separating-mixtures/) - ↑ back to [Chemistry](https://md.mova.elamur.ai/free/en/corpora/school/chemistry/)