Page 1: Probe and Ponder
Q1: What is happening in the picture? Answer: The picture shows people collecting salt. They likely use sea water, allow it to evaporate in shallow pits, leaving the salt (solute) behind. This demonstrates the separation of a dissolved solid from a liquid solvent.
Q2: What happens when you add too much sugar to tea? Answer: When you add too much sugar, the solution becomes saturated. The extra sugar stops dissolving and settles at the bottom.
- Solution: You can dissolve it by heating the tea (increasing temperature increases solubility).
Q3: Why do sugar/salt dissolve in water but not oil? Answer: Water is a polar solvent (“like dissolves like”), good for dissolving ionic/polar substances like salt and sugar. Oil is non-polar and cannot break the bonds in salt/sugar crystals effectively.
Q4: Why are water bottles tall and cylindrical? Answer: Cylindrical shapes are structurally strong (withstand pressure evenly), easy to hold, and efficient for packing/transport compared to spheres which would roll away and waste space between them.