Question

Half of a sample of cobalt-60 decays after 5.26 years to form atoms of another element. Half of a sample of iodine-131 decays after 8.1 days to form atoms of another element. Which best explains this difference? 1Choice 1 Iodine-131 has a smaller atomic number than cobalt-60. 2Choice 2 Iodine-131 has a shorter half-life than cobalt-60. 3Choice 3 Iodine-131 has a smaller atomic mass than cobalt-60. 4Choice 4 Iodine-131 has half the radioactive energy of cobalt-60.

Answer 1

Answer:

Iodine-131 has a shorter half-life than cobalt-60.

Explanation:

We are given;

• Half of a cobalt-60 sample decays after 5.26 years
• Half of an Iodine-131 sample decays after 8.1 days

We are supposed to explain the difference between the two instances;

We need to define half life;

• Half life is the time half of a given sample takes to decay leaving the other half of it.
• Therefore;

• If half of a cobalt-60 sample decays after 5.26 years then the half life of cobalt-60 is 5.26 years.
• On the other hand, if half of an Iodine-131 sample decays after 8.1 days, then the half life of Iodine-131 is 8.1 days.

• We can therefore, conclude that, Iodine-131 has a shorter half-life than cobalt-60.