Lesson 8: The Earth's Internal Heat

Question 1

a very thin layer when compared to the 3 other layers of the Earth

Answer 1

crust

Question 2

the largest layer of the earth being a estimated 1800 miles thick

Answer 2

mantle

Question 3

very hot dense rock

Answer 3

magma

Question 4

the mantle is kept in a

Answer 4

semi-liquefied state

Question 5

composed of very hot dense rock called magma, because of the high
temperatures with the Mantle, the rock is kept in a semi-liquefied state.

Answer 5

mantle

Question 6

composed of liquefied metals such as nickel ad iron. It is kept in it liquefied
state because of the immense heat with this layer

Answer 6

outer core

Question 7

also composed
of metals however they are not kept in a liquefied state. It is believed that the
temperature and pressure at depth is so great that the metals are squeezed tightly
together restricting movement, so much that the particles have to vibrated in place
almost like a soild structure.

Answer 7

inner core

Question 8

sources of heat in our planet

Answer 8

primordial and radiogenic heat

Question 9

the internal heat energy that gradually
gathered together by means of dispersion in the planet during its few million years
of evolution

Answer 9

primordial heat

Question 10

The major contribution of this internal heat
is the

Answer 10

accretional energy

Question 11

the energy deposited during the early formation of a planet

Answer 11

accretional energy

Question 12

a storage of primordial heat that originates from times of accretion when
kinetic energy of colliding particles was transformed into thermal energy.

Answer 12

the core

Question 13

the heat of the core takes ______ years to reach the surface of the Earth

Answer 13

tens of thousands of years

Question 14

the thermal energy released as a result of spontaneous
nuclear disintegration

Answer 14

radiogenic heat

Question 15

natural radioactive elements inside the Earth that disintegrate; involved in radiogenic heat

Answer 15

uranium, thorium, and potassium

Question 16

a special kind of element because when it decays, heat
(radiogenic) is produced.

Answer 16

uranium

Question 17

approximate terawatts in the flow of heat in the Earth’s interior to its surface

Answer 17

47 terawatts

Question 18

Without the process of radioactive decay, there would be

Answer 18

fewer volcanoes and earthquakes and less formation of mountain ranges

Question 19

produced by the radioactive decay of isotopes in
the mantle and crust

Answer 19

radiogenic heat

Question 20

left over from the formation of
the Earth.

Answer 20

primordial heat

Question 21

three processes that can transfer heat

Answer 21

conduction, convection, and radiation

Question 22

governs the thermal conditions in almost entire solid portions of the
Earth and plays a very important role in the lithosphere. Its processes happen in the
earth’s surface.

Answer 22

conduction

Question 23

e defined as the process by which heat energy
is transmitted through collisions between neighboring atoms or molecules. Heat from
the Earth’s core and radiation from the Sun is transferred to the surface of
the Earth by this

Answer 23

conduction

Question 24

involves transfer of heat by the movement of mass, which is a more
efficient means of heat transport in the Earth compared to pure conduction; dominates the thermal conditions in the zones where large quantities of
fluids (molten rocks) exist, and thus governs the heat transport in the fluid outer
core and the mantle

Answer 24

convection

Question 25

causes the mantle to move slowly from the interior up to the surface, resulting in the movement of tectonic plates

Answer 25

convection current

Question 26

how are volcanoes formed in terms of convection?

Answer 26

hot materials are added at the edges of a plate and cools. these edges become dense by its exposure from the heat and sinks into the Earth at ocean trenches

Question 27

the least important mode of heat transport in the Earth. The process of
heat exchange between the Sun and the Earth controls the
temperatures at the Earth’s surface.

Answer 27

Radiation

Question 28

Inside the Earth, radiation is significant only in
the hottest parts of the

Answer 28

core and lower mantle

Question 29

When the land and water become
warm in summer, they emit

Answer 29

long-wavelength infrared radiation