Heat and Energy
When something is hotter, it has _________ energy than something that is colder.
(more or less)
More
True or False:
The molecules of something that is hot move slower than the molecules of something that is cold.
False! The molecules of something hot move FASTER than the molecules of something that is cold.
When two things have different levels of energy, energy transfer from the molecules with _______ energy to the molecules with _______ energy.
(low/high)
Energy transfer occurs in the direction of HIGH energy to LOW energy
What is the name we give to the energy of motion?
Kinetic Energy
What is the average of the following:
(1) (2) (3)
(2) (3) (1)
(2)
After a candle is blown out, the wax of the candle decreases in temperature. What happens to the molecules of the wax when the temperature of the wax decreases?
a The energy of the molecules of the wax decreases.
b The cold energy of the molecules of the wax increases.
c The energy of the molecules of the wax increases.
d The wax loses heat molecules.
a The energy of the molecules of the wax decreases.
Lin cooked a pot of soup, then put half the soup in the freezer for a while. Now the soup in the pot is hot, and the soup in the freezer is cold. What is the difference between the molecules of the soup in the pot and the molecules of the soup in the freezer?
a. The molecules of the soup in the pot are moving and the molecules of the soup in the freezer are not moving.
b. The molecules of the soup in the pot are moving faster than the molecules of the soup in the freezer.
c. There is no difference because all of the soup is made of the same type of molecules.
d. The molecules of the soup in the freezer are smaller than the molecules of the soup in the pot.
b. The molecules of the soup in the pot are moving faster than the molecules of the soup in the freezer
Joseph puts a piece of toast on a plate. The toast is hot from the toaster. When he puts the toast on the plate, the energy of the plate increases. What must be true of the energy of the toast?
a Its energy stays the same while the energy of the plate increases.
b Its energy decreases while the energy of the plate increases.
c Its energy increases while the energy of the plate increases.
d It is impossible to know without data on the number of molecules in each object.
c Its energy increases while the energy of the plate increases.
When a system is not at equilibrium and is becoming different over time, it is undergoing what?
Change
What is the average of the following:
(4) (6) (5) (4)
(5) (6) (4) (1) (1)
4
Nistu is cooking rice in a pot. When she leaves the pot on the stove for a while, the temperature of the rice increases. What happens to the molecules of the rice when the temperature of the rice increases?
a The energy of the molecules in the rice increases.
b The cold energy of the molecules in the rice decreases.
c The energy of the molecules in the rice decreases.
d More heat molecules combine with the molecules in the rice
a The energy of the molecules in the rice increases.
Rico and Bree are camping and have potatoes wrapped in foil to eat. Bree put her potato in the campfire for a while, but Rico did not. Now Bree’s potato has a high temperature. What is the difference between the molecules of the two potatoes?
a There is no difference because both potatoes are made of the same type of molecules.
b The molecules of Rico’s potato are smaller than the molecules of Bree’s potato.
c The molecules of Bree’s potato are moving and the molecules of Rico’s potato are not moving.
d The molecules of Bree’s potato are moving faster than the molecules of Rico’s potato.
d The molecules of Bree’s potato are moving faster than the molecules of Rico’s potato.
What is the name of the state a system reaches when its molecules have stopped transferring energy?
Equilibrium
What is the name we give to energy as heat?
It is also what we call the total kinetic energy of all molecules that make up a sample
Thermal Energy
What is the average of the following:
(5) (4) (2) (3)
(1) (3) (3) (1)
(5) (4) (2) (3)
3