Radioactivity and its uses

Question 1

What does an atom consist of?

Answer 1

• nucleus at the centre
• positively protons + neutrons = nucleons
• negatively charged electrons

Question 2

______ are atoms of the same element that have
the same number of protons but a different
number of neutrons

Answer 2

isotopes

Question 3

Mass number vs atomic number

Answer 3

• mass number is the number of protons + neutrons, located at the top of the element
• atomic number is the number of protons, located at the bottom of the element

Question 4

___________ __________ is a process by which the nucleus of an unstable atom loses energy by emitting radiation

Answer 4

Radioactive Decay

Question 5

What is an example of radioactive decay?

Answer 5

An isotope that spontaneously emits such radiation is considered radioactive

Question 6

The amount of time needed for radioactive nuclei to decrease to one half the original amount is called:

Answer 6

Half life of a radioactive isotope

Question 7

What makes radiation dangerous?

Answer 7

The penetrating power of the particles and rays

Question 8

The ability of particles/rays to pass
through air and other material is inversely related to their _______

Answer 8

masses

Question 9

List the three different types of radiation sources and what stops their radiation from passing through.

Answer 9

• Alpha particles: stopped by a sheet of paper
• Beta particles: stopped by a layer of clothing or a few millimeters of a substance such as aluminum
• Gamma rays: stopped by several feet of concrete or a few inches of lead

Question 10

Comparing half lives between iodine and Cesium/Caesium.

Answer 10

Iodine (I-131)
- half life of 8 days
- radioactive material decays faster
- Dangers are very immediate if you are very close to the source (Could dose you heavily (and fatally)) at a short time
- lasts only for a short time

Cesium/Caesium
- Half life of 30 years
- radioactive material decays slowly over time
- lower dose that will produce fewer health
effects but bioaccumulates in your bones, and once it is there, it increases your cancer risk for life.
- lasts longer (more individuals could be exposed to radiation).

Question 11

TRUE or FALSE: We safely absorb small amounts of radiation daily

Answer 11

TRUE

Question 12

single largest source of natural radiation is ______ _____ that could be trapped in our _____.

Answer 12

• radon gas
• homes

Question 13

List 4 diagnostic procedures where you’re exposed to radiation

Answer 13

1. PET scans
2. CT scans
3. Dental xrays
4. Xray scanners

Question 14

________ ______ is used to estimate the age of rocks, fossils and other objects based on the fixed decay rate of radioactive isotopes.

Answer 14

Radiometric dating

Question 15

What is the half life of C-14?

Answer 15

5730 years