What method of energy transfer does a radiator use to warm the air in a room?
convection
100
What is the law of conservation of energy?
Energy cannot be created or destroyed.
100
What kinds of substances can become magnets?
those that have unpaired electrons
100
Is rubber or plastic a good conductor of electricity?Why?
No, rubber or plastic is used as an insulator around wires that carry electricity.
100
Where in a substance is chemical energy stored?
It is stored in the bonds of the molecules.
200
How was thermal energy transferred to the sidewalk in the first place?
by radiation from the sun
200
How could you increse the potential energy of an object?
raise the object; increase its mass.
200
Why don't magnets attract paper?
magnets attract only other magnetic materials.
200
What gives a battery potential energy?
the position of electrons - an imbalance of electrons between its two poles
200
Does burning fossil fuel use or produce energy? What kind of energy?
yes; heat energy
300
When you step on a sidewalk that has been warmed by sunlight, how is the energy transferred to your feet?
by conduction from the sidewalk
300
How are kinetic and potential energy smilar?
Both have the ability to cause changes in matter. Both can change into other forms of energy.
300
What do the lines of iron filings between the magnets show?
They show the lines of force.
300
What is a series circuit?
a circuit in which all the devices are connected in a row
300
What are some things in which chemical energy is stored?
Chemical energy is stored in batteries, in the molecules of fossil fuels, and in food.
400
What is measured by temperature?
the average kinetic energy of particles in in an object
400
How does kinetic energy differ from potential energy?
Kinetic energy depends on an object’s motion while potential energy depends on its position or condition.
400
The ends of two magnets are attracted to each other. What do you know about these ends?
They are opposite poles of the magnets: north-seeking and south-seeking.
400
Why are ther two wires to every electric device?
An electric current requires a conductor to travel through and will only flow through a complete circuit.
400
Why are fission and fusion called "nuclear" energy?
They are both produced by changes to the nucleus of an atom.
500
If one object is warmer than another one, what do you know about the particles in the warmer object?
They are moving faster on average than the particles in the cooler object.
500
Do plants have potential energy? Why?
Yes, they store food they make. They use the potential energy to grow and reproduce. Animals that eat plants also use this energy, changing some of it to kinetic energy.
500
What causes ab substance to lose its magnetism?
The domains of its electrons return to a random, unaligned pattern.
500
Why aren't all the appliances in your home connected in a series circuit?
They could not be individually switched in a series circuit; if one appliance stopped working, it would break the entire circuit.
500
How can you predict whether or not energy will be released in a chemical reation?
If the products contain less chemical energy than the reactants, energy will be released.