Chapter 10 Study Guide
Answer Key
Mrs. Malcolm’s 7th Grade Science
#1 and #2
• 1. ALL VOCABULARY! As usual, vocabulary
will make an appearance in either matching,
multiple choice, or short answer questions.
• 2. Key Questions! These are a great way to
review, and there are only 6 in this chapter!
#3
• 3. What does the Law of Conservation of
Energy state?
#3 Answer
• That energy is neither lost nor created during
an transformation.
#4
• 4. The total energy of all the particles in a
substance is called
__________________________.
#4
• The total energy of all the particles in a
substance is called Thermal Energy.
#5
• 5. What is temperature? What is heat?
#5 Answer
• Temperature: A measure of how hot or cold
something is compared to a reference point;
also the measure of the total amount of
kinetic energy.
• Heat: the transfer of thermal energy from a
warm object to a cooler object.
#6
• 6. What is a solid? A liquid? A gas? Give an
example of each.
#6
• Solid: Definite shape and volume; desk, rocks,
wall, baseball, carbon…
• Liquid: A definite volume but no definite
shape; water, juice, soda….
• Gas: Has neither a definite shape nor definite
volume; oxygen, air, nitrogen…
#7
• 7. In a system, when energy is transformed
from one form to another, the total energy is
____________________________.
#7 Answer
• 7. In a system, when energy is transformed
from one form to another, the total energy is
conserved.
#8
• 8. In a flashlight, ______________________
energy in the batteries is transformed into
electrical energy.
#8 Answer
• In a flashlight, chemical energy in the batteries
is transformed into electrical energy.
#9
• 9. What is nuclear energy?
#9 Answer
• The energy that is stored in the nucleus of an
atom.
#10
• 10. What is friction? How does it confirm the
Law of Conservation of Energy?
#10 Answer
• The force that one surface exerts on another
surface when two surfaces rub against each
other. The heat produced by friction is
evidence that energy is conserved. See page
354!
#11
• 11. What are three factors that determine an
objects thermal energy?
#11 Answer
• 1. Temperature
• 2. Number of particles
• 3. How the particles are arranged
#12 and #13
Beaker 1
Mass of
30
substance (g)
Temperature 200
in C
Beaker 2
Beaker 3
30
60
100
200
Use the following table to answer questions 12 and 13 about
thermal energy.
12. Which beaker has the highest amount of thermal energy?
________________
Explain your answer:
13. Which beakers contain the substance with the same
average kinetic energy?
#12 and #13 Answers
12. Which beaker has the highest amount of thermal
energy? Beaker 3!
Explain your answer:
Beaker 3 has the most particles (highest mass) and the
higher temperature.
13. Which beakers contain the substance with the same
average kinetic energy?
This is just like saying, “which two beakers have the
same temperature?” Because average kinetic energy
means temperature. So Beakers 1 and 3.
#14
• 14. If heat is transferred from a hot cup of
coffee to the surrounding cooler air, the
temperature of the coffee will (increase /
decrease).
#14 Answer
• If heat is transferred from a hot cup of coffee
to the surrounding cooler air, the temperature
of the coffee will decrease.
#15
• 15. Suppose you leave a glass of ice-cold soda
on a table in a warm room. In what
direction(s) will heat be transferred in this
system? When does heat transfer stop?
#15 Answer
• Think back to page 359
and the BBQ dinner. This
ice-cold soda is a lot like
the iced tea.
• Heat will be transferred
from the table and
surrounding air into the
colder soda.
• It will continue to transfer
till the soda, air, and table
are the same temperature.
#16
• 16. Heat transfer occurs in what direction?
#16 Answer
• Heat always transfers from the warmer object
to the cooler object.
#17
• 17. What are the three main ways that heat is
transferred? Define them.
• a.
• b.
• c.
#17 Answer
• A. Convection: a type of heat transfer that
occurs only in fluids such as water and air.
• B. radiation: the transfer of energy by
electromagnetic waves.
• C. Conduction: transfers het from one particle
of matter to another within an object or
between two objects.
#18
• 18. What is absolute zero?
#18 Answer
• The temperature at which no more energy can
be removed from matter.
#19
• 19. Describe how a convection current works?
#19 Answer
• When air is heated, the particles spread out
and the air becomes less dense. This allows
the air to rise. When it gets away from the
heat source, the air cools and sinks. This
creates a current.
#20
• 20. What heat transfer is occurring in C?
Where else in the picture is it occurring?
#20 Answer
• C is conduction. This is happening throughout
the pan as the particles within the pan are
transferring energy to one another. Also, you
could say it is happening between the heating
element and the pan.
#21
• 21. You need to be able to identify the
different types of heat transfer!
If you don’t study….