Pretest Answers

Manganese- 52 has a half-life of 6 days. How many days would a scientist have to wait for the radioactivity to be 12 point 5 percent the starting amount?

Which best describes the results of Becquerel’s experiments?

Which describes the experiments of Becquerel and the Curies?

Elemental carbon has 6 protons and 6 neutrons. This is often described as carbon-12. Carbon-13 has 6 protons and 7 neutrons, while carbon-14 has 6 protons and 8 neutrons. Based on the trend with carbon and the fact that plutonium has 94 protons, how many neutrons are in radioactive plutonium-244?

Jai was measuring the radioactivity of different radioactive isotopes. Isotope A had a starting radioactive level of 50 g, and after 4 days it measured at 30 g. Isotope B had a starting radioactive level of 75 g, and after 4 days it measured at 25 g. Which best explains the isotopes?

Which is one use for radioactive isotopes?

The starting amount of radioactive iodine- 131 was 250 g The half-life is 8 days. When Leslie measured the amount, she measured 15 point 6 2 5 g of radioactive iodine. How many days have elapsed between measurements?

What was the commonality between Becquerel and the Curies in terms of their work?

The Curies took pure uranium and a uranium-containing substance. When they measured the amount of radioactivity, there was more in the uranium-containing substance than the pure uranium. Which idea did the Curies most likely develop?

How can doctors best detect medical problems?