Changes & Separation Vocabulary
Use process words for changes of state and separating materials (dissolve, solution, soluble, insoluble, evaporate, condense, melt, freeze, filter, sieve, mixture, separate) and understand exactly what each one describes, including the difference between dissolving and melting.
What a learner can do afterwards
- Distinguish 'dissolve' from 'melt' correctly in context and explain the difference
- Use 'soluble' and 'insoluble' accurately when describing whether a material dissolves in water
- Explain the difference between evaporation and condensation using the correct terms
1 · Read
A mixture is different things put together without changing what they are. Salad is a mixture. So is sand stirred into water. You can often get the parts back. A sieve has holes: small bits fall through and big bits stay in it. Filtering means pouring a mixture through paper or a strainer. The liquid passes through and the solid bits stay behind.
Dissolving and melting can look alike, but they are not the same. When sugar dissolves in water, it breaks into pieces too small to see. It is still sugar, spread evenly through the water. Water with something dissolved in it is a solution. When ice melts, warmth turns it from a solid into a liquid. That is a change of state. Dissolving needs a liquid to mix into, not heat.
Mia stirs a spoonful of sugar into her warm tea. The sugar seems to vanish, but the tea tastes sweet. The sugar did not melt. It dissolved into the water, because sugar is soluble. If Mia stirred in sand instead, the sand would just sink. Sand is insoluble: it never dissolves.
Evaporate and condense are opposites. When a puddle dries up in the sun, the water evaporates: it turns into an invisible gas called water vapor. When water vapor touches something cold, like a glass of ice water, it condenses back into liquid drops.
Dissolving mixes into a liquid, melting changes solid to liquid with heat, and evaporating and condensing are opposite changes between liquid and gas.
Readings 'Dissolve or melt?' and 'Getting the parts back' are original to this dataset.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.