Chem 116 Exam 4 with answers |\ |\ |\ |\ |\
The major part of the average exposure of humans to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
radiation comes from - CORRECT ANSWERS ✔✔naturally
|\ |\ |\ |\ |\ |\ |\
occurring sources |\
All of the following are known to be forms of ionizing
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
radiation except - CORRECT ANSWERS ✔✔radio waves
|\ |\ |\ |\ |\ |\
The following nuclear reaction is an example of
|\ |\ |\ |\ |\ |\ |\ |\
226/88Ra->4/2He + 222/86Rn - CORRECT ANSWERS |\ |\ |\ |\ |\ |\
✔✔alpha decay |\
214/83 Bi decays by beta emission. The product is -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔214/84 Po |\ |\ |\
Which of the following particles has a mass of 1 amu and
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
a charge of 0 - CORRECT ANSWERS ✔✔neutron
|\ |\ |\ |\ |\ |\ |\
Phosphorous-30 decays by positron emission. The product |\ |\ |\ |\ |\ |\
is - CORRECT ANSWERS ✔✔Silicon-30
|\ |\ |\ |\ |\
, One difference b/w a chemical reaction & a nuclear
|\ |\ |\ |\ |\ |\ |\ |\ |\
reaction is that in nuclear reaction - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔atoms often change from one element to another |\ |\ |\ |\ |\ |\ |\
After 5 half-lives, what percentage of the original
|\ |\ |\ |\ |\ |\ |\ |\
radioactive isotope remains in a sample? - CORRECT |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔3.13% |\
Sodium-24 has a half-life of 15 hours. How much of a |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
20mg sample would remain after 2 half-lives? - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔5 mg |\ |\
A piece of fossilized wood has a carbon-14 radioactivity
|\ |\ |\ |\ |\ |\ |\ |\ |\
that is 1/4 that of new wood. The half life of carbon-4 is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
5730 years. How old is the cloth? - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔2 x 5730 = 11,460 years |\ |\ |\ |\ |\
Radioisotopes have been used to determine the age of all |\ |\ |\ |\ |\ |\ |\ |\ |\
of the following except - CORRECT ANSWERS ✔✔living
|\ |\ |\ |\ |\ |\ |\ |\ |\
plants
in 1932, James Chadwick bombarded beryllium-9 with
|\ |\ |\ |\ |\ |\ |\
alpha particles. One product was a neutron. This lied to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
the direct experimental verification of the existence of
|\ |\ |\ |\ |\ |\ |\ |\
neutrons. The other product of Chadwick's nuclear |\ |\ |\ |\ |\ |\ |\
reaction was - CORRECT ANSWERS ✔✔carbon-12 |\ |\ |\ |\ |\
The major part of the average exposure of humans to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
radiation comes from - CORRECT ANSWERS ✔✔naturally
|\ |\ |\ |\ |\ |\ |\
occurring sources |\
All of the following are known to be forms of ionizing
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
radiation except - CORRECT ANSWERS ✔✔radio waves
|\ |\ |\ |\ |\ |\
The following nuclear reaction is an example of
|\ |\ |\ |\ |\ |\ |\ |\
226/88Ra->4/2He + 222/86Rn - CORRECT ANSWERS |\ |\ |\ |\ |\ |\
✔✔alpha decay |\
214/83 Bi decays by beta emission. The product is -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔214/84 Po |\ |\ |\
Which of the following particles has a mass of 1 amu and
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
a charge of 0 - CORRECT ANSWERS ✔✔neutron
|\ |\ |\ |\ |\ |\ |\
Phosphorous-30 decays by positron emission. The product |\ |\ |\ |\ |\ |\
is - CORRECT ANSWERS ✔✔Silicon-30
|\ |\ |\ |\ |\
, One difference b/w a chemical reaction & a nuclear
|\ |\ |\ |\ |\ |\ |\ |\ |\
reaction is that in nuclear reaction - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔atoms often change from one element to another |\ |\ |\ |\ |\ |\ |\
After 5 half-lives, what percentage of the original
|\ |\ |\ |\ |\ |\ |\ |\
radioactive isotope remains in a sample? - CORRECT |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔3.13% |\
Sodium-24 has a half-life of 15 hours. How much of a |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
20mg sample would remain after 2 half-lives? - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔5 mg |\ |\
A piece of fossilized wood has a carbon-14 radioactivity
|\ |\ |\ |\ |\ |\ |\ |\ |\
that is 1/4 that of new wood. The half life of carbon-4 is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
5730 years. How old is the cloth? - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔2 x 5730 = 11,460 years |\ |\ |\ |\ |\
Radioisotopes have been used to determine the age of all |\ |\ |\ |\ |\ |\ |\ |\ |\
of the following except - CORRECT ANSWERS ✔✔living
|\ |\ |\ |\ |\ |\ |\ |\ |\
plants
in 1932, James Chadwick bombarded beryllium-9 with
|\ |\ |\ |\ |\ |\ |\
alpha particles. One product was a neutron. This lied to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
the direct experimental verification of the existence of
|\ |\ |\ |\ |\ |\ |\ |\
neutrons. The other product of Chadwick's nuclear |\ |\ |\ |\ |\ |\ |\
reaction was - CORRECT ANSWERS ✔✔carbon-12 |\ |\ |\ |\ |\
