X-rays

Question 1

what are x-rays?

Answer 1

are a type of radiation called electromagnetic waves. X-rays imagine creates picture of inside your body

Question 2

why are x rays useful?

Answer 2

• helped discover the structure of DNA
• disease diagnosis
• allow analysis for unknown compunds

Question 3

what are the two types of x-rays?

Answer 3

x-ray diffraction (XRD)

x-ray fluorescence (XRF)

Question 4

what is the difference between XRD and XRF?

Answer 4

x ray diffraction distinguishes compounds while x ray fluorescence identifies the element present in a compound

Question 5

what is x ray diffraction?

Answer 5

• analyses and identifies crystalline compounds (ions, molecules and atoms)
• measures sample purity

Question 6

what is the machine of x ray diffraction?

Answer 6

• x ray tube is the source of x rays
• x ray filter produces monochromatic x rays
• sample holder holds the sample
• x ray detector detects x rays

Question 7

process of x ray diffraction?

Answer 7

1. cathode ray tube heats a filament to produce electrons
2. electrons are bombarded to the target, by voltage.
3. the dislodging of electrons produces on x ray spectra
4. x rays interact with atoms and diffracts. beams are recorded
5. recorded signals produce 3d images

Question 8

pros and cons of x ray diffraction?

Answer 8

\+ simple sample prep
\+ results are easy to interpret
\+ specific results
- sample needs to be in a fine powder
- reduced accuracy if sample is mixed

Question 9

what is x ray fluorescence?

Answer 9

effective quantitative technique that determines the elemental composition of any material

Question 10

what is the process of x-ray fluorescence?

Answer 10

1. x rays collide with an atom
2. an electron is ejected from a lower energy level and a space is created
3. an electron from a higher energy level falls into this place
4. the difference in energy releases secondary x rays
5. the secondary x rays is the characteristics of the element

Question 11

pros and cons of x ray fluorescence?

Answer 11

+ non-destructive to the sample
+ simple and fast prep
+ no recalibration is needed
- quantity of sample will affect reliability
- weight will also effect reliability
- expensive and consuming to use on complex samples

Question 12

how does high atomic mass affect x rays?

Answer 12

high atomic mass = greater x ray absorption = higher contrast images

Question 13

how does fat affect x rays?

Answer 13

fat, muscle or air = reduced travel of x rays = poor images

Question 14

what is mammography?

Answer 14

breast cancer detection and diagnosis

Question 15

how are x rays used in therapeutic medicine?

Answer 15

• radiation therapy can destroy cancerous tumours by damaging their DNA