4.4+ 4.3 Flashcards Preview

Chem 100 > 4.4+ 4.3 > Flashcards

Flashcards in 4.4+ 4.3 Deck (15):
1

half life

length of time it takes for one half of a radioactive sample to decay

2

decay curve

shows the decay of radioactive isotopes

3

carbon dating

technique used to date ancient specimen

4

what formula do you use to date the age of a specimen using carbon

(1/2)^n x 100

5

why are radioactive isotopes used in medicine?

short half lives
they have the same chemistry in the body as the nonradioactive atoms

6

scan

image of site in body created by detection of radiation from radioactive isotopes that accumulated in that site

7

How do radiologists know if there is a problem when examining scans?

areas of decreased or increased radiation may indicate problem

8

what can radioactive particle can provide images of an organ? how?

gamma rays from organ can be used to expose a photographic plate providing an image of the organ

9

Positron Emission Tomograpghy (PET)
uses which radiation particle? and how

positron,
they combine with electrons to produce gamma rays that will be detected

10

examples of positrons for PET

carbon-11
oxygen-15
nitrogen-13
fluorine-18

11

Which positron is used for brain study function, blood flow or metabolism?

fluorine-18

12

Magnetic Resonance Imaging (MRI)
how is it done?

based on absorption of energy when protons in Hydrogen are places in a strong magnetic field.

13

which type of scans do not involve x-ray radiation?

MRI

14

which scan is the least invasive?

MRI

15

what aligns hydrogen against magnetic field? (MRI)

short pulses of energy aligns them