Radiology intro

Question 1

Who discovered x-ray? Where? When? What was the first radiograph taken of?

Answer 1

Wilhelm Conrad Roentgen, 1895 in Germany. Radiograph of his wife’s hand

Question 2

Properties of x-ray..

Answer 2

Forms electromagnetic radiation, Causes ionisation, undetectable to human senses.

Question 3

Basic production of x-ray

Answer 3

Electrons fired at atoms, creating kinetic energy resulting in electromagnetic radiation and heat. Then the x-ray photons are aimed at a subject

Question 4

What does the atom consist of?

Answer 4

Protons and Neutrons (in the central nucleus) and Electrons (orbiting shells)

Question 5

Atomic number (z) represents…

Answer 5

Number of protons

Question 6

Mass number (A) represents…

Answer 6

Number of protons and neutrons

Question 7

Isotopes and Radio-isotopes

Answer 7

Isotopes - same elements with different number of neutrons

Radio-isotopes are unstable that undergoes radioactive decay

Question 8

What does the number of electron determine?

Answer 8

Chemical properties of an atom

Question 9

“Ground state” is…

Answer 9

Neutral atom.

Number of electron = Number of protons

Question 10

What is ionisation?

Answer 10

Ionisation is removing or addition of electrons to an atoms

Question 11

Atom minus an electron is…

Answer 11

Positive ion (cation)

Question 12

Atom added on with electron is…

Answer 12

Negative ion (anion)

Question 13

What is the most inner shell labelled? and the other shells?

Answer 13

Innermost K - holds 2 electrons.
Then L - 8 electrons
Then M - 18 electrons
then N, O etc

Question 14

What does binding energy depend on?

Answer 14

i) Which shell electron is in

ii) how many protons and neutrons are in the nucleus

Question 15

Alpha particles radioactive emissions

Answer 15

2 protons and neutrons. Large, positive, extensive ionisation

Question 16

Beta particles radioactive emissions

Answer 16

Electrons.

Small, negative, ionisation

Question 17

Gamma particles radioactive emissions

Answer 17

Electromagnetic radiation, ionisation

Question 18

When is ionisation a problem?

Answer 18

When it occurs in living cells. Causes DNA damage.

Indirect: produces free radicals that leads to DNA damage.

Question 19

Electromagnetic radiation properties:

Answer 19

No mass, No charge, can travel in a vacuum

Question 20

What is frequency?

Answer 20

Number of cycles per unit time. Measured in hertz, Hz/s

Question 21

What is wavelength?

Answer 21

Distance travelled per cycle. Measured in metres, m

Question 22

Formula for speed?

Answer 22

speed = frequency x wavelength

Question 23

Flow of electric charge known as? .. measured in..?

Answer 23

Current. Measured in amps, A

Question 24

How many direction current have?

Answer 24

Two.
Direct - unidirectional (batteries)
Alternative - reverses (mains)

Question 25

What is voltage?

Answer 25

Difference in electrical potential between 2 points in electrical field

Question 26

What is created when voltage applied to wire coil?

Answer 26

Electrons vibrate and create current

Question 27

What is the result of the vibrating electrons produce heat and light?

Answer 27

Wire becomes hot and gives off light

Question 28

Radiant heat causes movement of air molecules result in ...

Answer 28

surrounding area becoming hot

Question 29

What happens to wavelength when frequency increases?

Answer 29

Decreases (vice versa)