Home Chapter 30 Practice Questions

# Practice Questions

This activity contains 25 questions.

## What is the atomic number of 23692U?

 92 144 236 328

## What is the atomic mass number of 23692U?

 92 144 236 328

## What is the neutron number of 23692U?

 92 144 236 328

## What is the mass of 23692U to the nearest u?

 328 u 236 u 235 u 144 u

## What is the actual mass of 23692U?

 236 u 236.0001 u 236.038735 u 236.045562 u

## What is the answer to Question 5 in kilograms?

 3.9195366 x 10-25 Kg 3.9296766 x 10-26 Kg 3.9431411 x 10-25 Kg 3.9395386 x 10-24 Kg

## Which of the following is not a reason why the answers to Question 4 and 5 are not exactly equal?

 The mass of the proton plus the electron is not exactly 1 u. The mass of the neutron is not exactly 1 u. Several different isotopes of uranium exist in nature. E = mc2

## The mass of 126C is exactly 12.000000 u. Why?

 It is the only existing isotope of carbon. That is how the mass unit u is defined. The relativistic effect cancels out the mass defect. Because of limited experimental accuracy.

## What element is given by 4020X, where X stands for the element symbol, but is not the symbol?

 calcium zirconium xenon iron

## What is the binding energy of the 126C nucleus?

 12 MeV 937 keV 92 MeV

 alpha beta gamma delta

## What is the half-life of 9038Sr?

 23 s 11.8 days 29.1 yr 4.1 x 109 years

## What isotope results from the decay of 9038Sr?

 9037Rb 9039Y 8939Y 8938Sr

## If you start out with 8 x 1024 9038Sr, how many do you have after two half-lives?

 2 x 1024 8 x 106 2 x 106

## The mass of 9038Sr is 89.907737 u and the mass of the atom its beta decays to is 89.907151 u. What is the energy released in the decay?

 1.2 MeV 112 keV .546 MeV 1.8 MeV

## How many 9038Sr atoms would there be in 1 gram of the substance?

 1.7 x 1012 6.7 x 1021 6.7 x 1024 1.7 x 1026

## What is the decay constant for 9038Sr?

 29.1 years .0238 year-1 .0344 year-1 .52 year-1

## How long would it take a sample of 7 x 1021 of 9038Sr atoms to decrease to 6 x 1010 atoms?

 29.1 years 107 years 1070 years 1000000 years

## What would be the activity of the strontium sample at the end of the period covered in Question 18?

 45 decays/s 1130 decays/s 21100 decays/s 6.7 x 1021 decays/s

## 2211Na decays via positron emission into

 2311Na 2212Mg 2210Ne 2311Ne

## 22890Th emits a gamma ray. The resulting nucleus is

 22890Th 22891Pa 22990Th 23092U

## In beta decay an electron is emitted along with the daughter nucleus. What is the other particle emitted?

 beta particle antineutron neutrino antineutrino

## 253100Fm decays via electron capture. The resulting element is

 25299Es 25499Es 25399Es 253101Md

## 21084Po decays by alpha decay. The resulting isotope is

 21082Pb 21081Bi 20881Bi 20682Pb

## What is the energy released in the above decay?

 234 MeV 23.4 MeV 5.4 MeV 13.6 eV