It’s Still There!
It's still there teaches Grade 5 students that dissolving is a physical change — matter that dissolves does not disappear; it just breaks into invisible particles. Sugar dissolved in tea cannot be seen, but it is still there: you can taste it, and if you measure the mass before and after mixing, it is identical. The total weight of water plus sugar equals the weight of the sweet water. This conservation of mass evidence from Amplify Science (California) Grade 5, Chapter 2, proves that dissolved matter persists even when invisible.
Key Concepts
It is easy to think that when sugar dissolves in tea, it is gone forever. But we know it is still there because we can taste it.
Dissolving is a physical change where matter breaks into invisible particles . The mass (weight) of the mixture proves this. If you weigh the water and the sugar separately, and then weigh the sweet water after mixing, the weight is the same. The matter didn't disappear; it just changed form.
Common Questions
What happens to sugar when it dissolves in water?
Sugar breaks apart into tiny invisible particles that spread evenly through the water. The sugar is still there — you can taste it — but you cannot see it because the particles are too small.
How does mass prove that dissolved sugar is still there?
If you weigh water and sugar separately, then mix them and weigh the solution, the mass is the same. Matter cannot disappear; the sugar's mass is still present in the solution.
Is dissolving a physical or chemical change?
Dissolving is a physical change. The identity of the substance does not change — sugar particles are still sugar molecules, just spread out. No new substance is formed.
What is conservation of mass?
Conservation of mass is the scientific law that states matter is neither created nor destroyed in physical or chemical changes. The total mass before equals the total mass after.
Can you get dissolved sugar back?
Yes. You can evaporate the water, leaving the sugar behind. This is possible because dissolving is a physical change — the sugar's identity is preserved.
What grade and chapter covers the concept that dissolved matter is still present?
Grade 5, Chapter 2 of Amplify Science (California): Why do some salad dressings have sediments, and others do not?