Radiation, Conduction And Convection

Question 1

What is radiation?

Answer 1

Radiation is energy that comes from a source and travels through some material or through space.

Question 2

Types of radiation

Answer 2

Light, heat and sound.

Question 3

How is ionizing radiation produced?

Answer 3

Ionizing radiation is produced by unstable atoms. Unstable atoms differ from stable atoms because they have an excess of energy or mass or both.

Question 4

Are unstable atoms radioactive?

Answer 4

Unstable atoms are said to be radioactive. In order to reach stability, these atoms give off, or emit, the excess energy or mass. These emissions are called radiation.

Question 5

What is natural background radiation exposure?

Answer 5

It comes from cosmic rays and from naturally occurring radioactive materials contained in the earth and in living things.

Question 6

What is irradiation?

Answer 6

Irradiation is exposure to penetrating radiation. Irradiation occurs when all or part of the body is exposed to radiation from an unshielded source.

Question 7

Does external irradiation make a person radioactive?

Answer 7

External irradiation does not make a person radioactive.

Question 8

When does radioactive contamination occur?

Answer 8

Contamination occurs when material that contains radioactive atoms is deposited on skin, clothing, or any place where is it not desired.

Question 9

Can radioactive contamination spread?

Answer 9

If is important to remember that radiation does not spread or get “on” or “in” people; rather it is radioactive contamination that can spread.

Question 10

What happens when a person is contaminated with radioactive materials?

Answer 10

A person contaminated with radioactive materials will be irradiated until the source of radiation (the radioactive material) is removed.

Question 11

How does a person become externally contaminated?

Answer 11

A person is externally contaminated if radioactive material is on skin or clothing.

Question 12

How does a person become internally contaminated?

Answer 12

A person is internally contaminated if radioactive material is breathed in, swallowed, or absorbed through wounds.

Question 13

How does the environment become contaminated?

Answer 13

The environment is contaminated if radioactive material is spread about or uncontained.

Question 14

What is conduction?

Answer 14

Conduction is the process by which heat or electricity is directly transmitted through the material of a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

Question 15

What is the process of conduction?

Answer 15

Conduction is the process by which sound waves travel through a medium. The transmission of impulses along nerves.

Question 16

Where does conduction occur?

Answer 16

Conduction occurs in solids, liquids, and gases. However, solids transfer energy most efficiently since the molecules in solids are most tightly packed, and the molecules are closer together, as shown in this figure.

Question 17

Definition of conduction

Answer 17

Conduction is the transfer of energy in the form of heat or electricity from one atom to another within an object by direct contact.

Question 18

Where does conduction occur (cont.)

Answer 18

For liquids and gases, the density of the particles are generally lower than those of solids and the particles are farther apart, so the energy transfer is less efficient.

Question 19

Two main types of conduction

Answer 19

• Conduction of heat

- Conduction of electricity

Question 20

When does conduction of heat occur?

Answer 20

Conduction of heat occurs when molecules increase in temperature; they vibrate, and this vibration and movement passes the heat energy to the surrounding molecules.

Question 21

Examples of conduction

Answer 21

Some examples of conduction of heat are accidentally touching a hot pot, or when a heating pad is applied to you directly and warms your muscles.

Question 22

When does conductions of electricity occur?

Answer 22

Conduction of electricity occurs due to the movement of electrically charged particles through a medium. This movement can result in an electric current, which may be carried by electrons or ions.

Question 23

Example of electrical conduction

Answer 23

An example of electrical conduction is when you accidentally get electrocuted when you touch a live wire because your body contains water, which is a conductor of electricity.

Question 24

Example of electrical conduction

Answer 24

When electricity passes through wires, which are conductors, so we can watch TV or use a computer.

Question 25

How to know if a object is a good conductors of heat.

Answer 25

In general, if an object is a good conductor of heat, it usually follows that the object is also a good conductor of electricity.

Question 26

Materials classified as good conductors of heat

Answer 26

Materials are classified as good conductors if they allow the flow of charged particles and electrical energy to freely pass through them.

Question 27

Examples of good conductors of heat

Answer 27

Some examples of good conductors are generally metals, such as silver, copper, iron, and aluminium. Their degree of conductivity differs based on the type of metal.

Question 28

Examples of good conductors of heat

Answer 28

Metals are generally good conductors of heat because at least one electron per atom is free to move about between atoms and transfer heat and electricity.

Question 29

What is the best conductor?

Answer 29

Silver

Question 30

What is convection?

Answer 30

The movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.