intro to radiology

Question 1

what is a radiograph?

Answer 1

an image produced by x-rays passing through and object and interacting with the photographic emulsion on a film

Question 2

why are X-rays used in dentistry?

Answer 2

teeth are mineralised tissues- different parts of the tooth will absorb differing amounts of radiation
caries=demineralisation=radiolucent
enamel-highly mineralised=radiopaque

Question 3

when was the first x-ray taken in dentistry?

Answer 3

1896

Question 4

what is the nucleus of an atom made up of?

Answer 4

protons (+) and neutrons (no charge)

Question 5

what charge does the nucleus of an atom have?

Answer 5

positive

Question 6

what is the nucleus of an atom surrounded by?

Answer 6

electron shells

Question 7

what do electron shells contain?

Answer 7

diff numbers of electrons that allow an atom to remain stable?

Question 8

what electron shell is closest to the nucleus?

Answer 8

K

Question 9

how many electrons do K and L energy shells have?

Answer 9

K-2
L-8

Question 10

can electrons exist between shells?

Answer 10

no- this is the forbidden zone
they can only move between shells if binding energy is overcome

Question 11

what is the atomic number of atoms?

Answer 11

Z- the number of protons in the nucleus

Question 12

what is the atomic mass number?

Answer 12

A-number of protons + no of neutrons

Question 13

what is an isotope?

Answer 13

same atomic number- but diff number of neutrons

Question 14

what is an ion?

Answer 14

a charged atom/molecule

Question 15

if there are more electrons than protons in an ion it is known as ?

Answer 15

an anion

Question 16

if there are more protons than electrons it is known as?

Answer 16

a cation

Question 17

what determines the chemical properties of an atom?

Answer 17

electrons

Question 18

an atom in its ground state is known as what?

Answer 18

neutral- number of electrons is the same as number of protons

Question 19

removing and adding electrons to an atom is known as what?

Answer 19

ionisation

Question 20

an atom that has lost an electron is known as what?

Answer 20

a cation- a positive ion

Question 21

an atom that has gained an electron is known as what?

Answer 21

an anion- a negative ion

Question 22

do electrons closest to the nucleus have more or less energy than those further away from the nucleus?

Answer 22

less energy than those further away

Question 23

when is ionisation a problem?

Answer 23

when it occurs in living cells
-can cause damage to tissue
-can damage DNA leading to cancer/tumours

Question 24

describe the order of electromagnetic spectrum?

Answer 24

radiowaves
microwaves
infrared
visible light
UV
X-rays
gamma rays

Question 25

what has longest wavelength and what has the shortest?

Answer 25

longest=radiowaves
shortest=gamma waves

Question 26

what part of spectrum has most and least energy?

Answer 26

least-radiowaves
most-gamma rays

Question 27

what does the electromagnetic spectrum describe?

Answer 27

the types of electromagnetic radiation

Question 28

what is electromagnetic radiation?

Answer 28

a stream of photons (energy)

Question 29

what are examples of ionising radiation?

Answer 29

UV
x rays
gamma rays

Question 30

what causes ionising radiation?

Answer 30

high energy photons cause ionisation of atoms- releasing chemicals and cause DNA damage

Question 31

what is needed for electrons to move through a current?

Answer 31

voltage (potential difference)

Question 32

are x-rays involved in radioactive decay?

Answer 32

no- only alpha, beta and gamma

Question 33

what are X-rays very similar to?

Answer 33

gamma

Question 34

are x rays fast or slow?

Answer 34

fast

Question 35

do x rays cause ionisation?

Answer 35

yes

Question 36

do X-rays have a weight, mass or charge?

Answer 36

no

Question 37

do x rays have the same energy values as gamma rays?

Answer 37

no- they are lower

Question 38

define the voltage?

Answer 38

the power that causes a current to flow or electrons to move from cathode to anode

Question 39

what is needed for electricity to flow?

Answer 39

a circuit