Vocabulary
What property describes how well a substance allows electricity to flow?
Electrical Conductivity
Which usually conducts electricity best: a metal wire, a tree, a sidewalk, or a plastic cup?
A metal wire
What type of energy moves from a warm drink into an ice cube?
Thermal energy
What does it mean when sugar dissolves in water?
The sugar spreads throughout the water to form a solution
What property describes how well a material transfers heat?
Thermal Conductivity
True or false: All substances conduct electricity equally well
False. Some are good conductors and others are poor conductors
What happens to an ice cube placed in a warm drink?
It shrinks as it melts
Which has the lowest solubility in water: drink mix, sugar, or a flower seed?
A flower seed
What property describes the ability of a substance to dissolve in a liquid?
Solubility
A lightbulb glows brighter when more electricity reaches it. What does its brightness help us compare?
Electrical conductivity
Does a material with low thermal conductivity transfer heat quickly or slowly?
Slowly
Salt collects at the bottom of a glass after more salt is added. What might this mean?
The water has become saturated and cannot dissolve more salt under those conditions
What do we call a material that does not allow heat to pass through easily?
Thermal Insulator
Four mystery substances produce 688, 1,075, 832, and 976 lumens. Which has the highest conductivity?
1,075
Why might a cooking utensil have a plastic or wooden handle?
Plastic and wood are poor thermal conductors, so they slow heat transfer
What is the difference between a soluble and an insoluble substance?
A soluble substance dissolves in a given liquid; an insoluble substance does not dissolve appreciably
Explain the difference between electrical and thermal conductivity
Electrical conductivity measures how well electricity flows through a material; thermal conductivity measures how well heat transfers through it
Design a simple investigation to compare the electrical conductivity of two materials.
Use a low-voltage battery, bulb, and wires. Place each material in the circuit separately, then compare whether or how brightly the bulb lights.
Two spoons, one metal and one wooden, sit in warm water. Which handle will usually become warm faster, and why?
The metal spoon because metal generally has higher thermal conductivity.
You add the same amount of sugar to equal amounts of warm and cold water. What could you investigate?
How water temperature affects the speed at which sugar dissolves