Changes & Separation Vocabulary
Use process vocabulary for changes of state and material separation — dissolve, solution, soluble, insoluble, evaporate, condense, melt, freeze, filter, sieve, mixture, separate — and understand precisely what each term describes, including the important distinction 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
The lesson
A mixture is what you get when you put different things together without changing what they are. Salad is a mixture. So is sand stirred into water. You can often separate a mixture and get the parts back. A sieve is a tool with tiny holes: it lets small bits through and catches the big ones. Filtering means pouring a mixture through paper or a strainer, so the liquid passes through while 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, just mixed evenly through the water, and water with something dissolved in it is called a solution. When ice melts, it changes from a solid into a liquid because it gets warm. Melting is a change of state. Dissolving is mixing into a liquid, no heat needed.
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.
Watch it
Where it sits
Learn first
Nothing; this is a starting point.
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.