MCQ
what is the penetration power of gamma rays?
option a : low
option b: medium
option c: high
-high power
airline pilots and flight attendants are oftenly & legally monitored for radiation exposure. explain why their job puts them at a higher risk of radiation exposure compared to other jobs
-pilots spend thousands of hours flying at high altitudes, where the Earth’s atmosphere is much thinner.
-thinner atmosphere = less shielding against cosmic rays from space
this exposes airline crews to significantly higher levels of natural background radiation than people at ground level.
what is the highest ionising type of radiation?
-alpha particles!
a radioactive substance has an initial activity of 400Bq. after 24 days, it’s activity drops to 50Bq. what is the half-life duration of this substance?
8days
what are two examples of manmade ionising radiation in our environment
i background radiation
ii network cell towers
iii fluorsecent light bulb ballasts
iv burning coal for electricity (also known as coal ash/fly ash)
option a: i and ii
option b: i and iii
option c: i and iv
-option c
during a type of cancer treatment : radiotherapy, a narrow, high-energy beam of gamma rays is directed at a tumor. although the treatment kills the cancer cells, patients often lose their hair & feel side effects such as feeling nauseous. why do these side effects occur?
-gamma radiation is ionising & doesnt separate between healthy and unhealthy cells.
-as the beam passes thru the body to reach the tumor, it unintentionally damages surrounding healthy, fast-dividing cells
name 3 safety measures when handling radioactivity sources & waste
-answers in pg243
a sample of a radioactive isotope is left in a lab for 40 days. After 40 days, the radiation activity of the sample drops to only 1/16 of its original value. calculate the number of half-lives & the half-life duration of this given isotope.
-4 number of half lives
-10 days durstion
what is the safe level of background radiation dosage per year
option a: < 1.752 mSv/year
option b: < 17.52 mSv/year
option c: < 1752 mSv/year
-option a
a community suggestion was made that the government should place gm counters at supermarket checkout lines to scan fruits and meat that have undergone gamma sterilization to protect consumers from buying radioactive food. Is this suggestion valid or invalid, and why, economically & scientifically
-thus suggestion is scientifically invalid & economically wasteful.
-food irradiation exposes food to energy waves, not the radioactive material itself; therefore, the food never becomes a radiation emitter. A gm counter at the supermarket would show nothing higher than normal natural background radiation.
it is understood that radioactive radiation is used in the preserving of some foods ex. gamma rays to kill bacteria.
what is the logo used to label the usage of radioactive radiation in food called?
-radura logo
the half-life of Iodine-131 is 8 days. if a hospital starts with a sample of 12g, how much of it will have decayed away after 16 days?
-9g
how many electrons are in one singular alpha participle
option a: 2 elections
option b: 1 electrion
option c: 0
-option c
a homeowner often worries that having a radioactive source inside their house will expose his family to dangerous radiation. Is this concern is scientifically valid & why?
-concern of this is invalid.
-alpha radiation has low penetrating power and is completely blocked by the plastic casing of the smoke detector & few centimeters of the air. it is not enough to penetrate human skin to cause any typa harm.
Antoine Henri Becquerel recieved the Novel Prize in Physics for the discovery he made.
what did he discover?
-a compound: uranium
an isotope has a half-life of 4 hours. If 5 g of the isotope remains after 12 hours, what was the initial mass of the sample?
-40g