The amount of time it takes for some of the nuclei in a sample of the isotope to decay
The amount of time it takes for half the nuclei in a sample of the isotope to decay
The amount of time it takes for half the electrons in a sample of the isotope to decay
the amount of time it takes to double the nuclei in a sample of the isotope to decay
The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?
100.0g
50.0 g
12.5 g
8.5 g
The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how much sample would be left after 3 half-lives?
1/2
1/3
1/8
1/16
Barium-122 has a half-life of 2 minutes. A fresh sample weighing 80 g was obtained. If it takes 10 minutes to set up an experiment using barium-122, how much barium-122 will be left when the experiment begins?
0.25 g
2.5 g
25 g
80 g
The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?
3.0 g
0.25 mg
0.25 g
0.3 g
If the half-life of uranium-232 is 70 years, how many half-lives will it take for 10 g of it to be reduced to 1.25 g?
1
2
3
4
What is the half-life of Iodine-131?
32 days
24 days
16 days
8 days
If one-fourth of a sample of carbon-14 is remaining then how many half-lives have passed?
1
2
3
4
Why do some elements have half-lives?
Their nuclei are unstable
Their electron cloud is unstable
Half of the atom gets stolen
They are Twizzlers that break in half
If one has 12 kg of Polonium after two half-lives have passed, how much Polonium did you start with?