S3.5.7 For the adult
Dissolving and solutions
Where does the salt go when I stir it into water, and does the cup weigh less?
What this chapter teaches
A solid that dissolves breaks into particles that spread among the liquid particles. The solid is the solute, the liquid is the solvent, and the mixture is the solution. Nothing is lost, so the mass stays the same.
Three questions to ask
There is no one right wording. Listen for the idea.
- Where do you think the salt goes when you stir it into water?
- Would the cup weigh less, the same or more after the salt dissolves? Why?
- What could you change to make sugar dissolve faster?
After the chapter, the learner can
- Use the words solute, solvent and solution correctly
- Test how warm water and stirring change how fast sugar dissolves
- Explain why mass stays the same when salt dissolves
What they copy into their notebook
A solute dissolves in a solvent to make a solution. Its particles spread among the solvent particles. Nothing is lost, so the mass stays the same. Warm water and stirring dissolve faster.