Chemistry and Nuclear Chemistry for Nursing School Entrance Exam Practice Problems

The study guide for these practice questions can be found at:

Chemistry and Nuclear Chemistry for Nursing School Entrance Exam Study Guide

Questions

1. The time required for of the atoms in a sample of a radioactive element to disintegrate is known as the element's
   1. decay period.
   2. life time.
   3. radioactive period.
   4. half-life.
2. The least penetrating radiation given off by a radioactive substance consists of
   1. alpha particles.
   2. beta particles.
   3. gamma rays.
   4. X-rays.
3. The half-life of a given element is 70 years. How long will it take 5.0 g of this element to be reduced to 1.25 g?
   1. 70 years
   2. 140 years
   3. 210 years
   4. 35 years
4. If element A gives off an alpha particle, what is the atomic number and mass of the resulting element B?

²¹⁰A₈₃

1. B²¹⁰₈₁
2. B²⁰⁶₈₁
3. B²⁰⁶₈₃
4. B²⁰⁴₈₁
5. If element B gives off a beta particle and gamma rays, what is the resulting element?

B²³⁸₉₂

1. B²³⁸₉₃
2. B²³⁴₉₀
3. B²³⁹₉₂
4. B²³⁹₉₁
6. What is the missing product?

X⁴²₁₇ → Y⁴²₁₈ + ?

1. He⁴₂
2.  
3. e⁰₁
4. β⁰_–1
7. What is the missing product?

A⁶⁰₂₄ → B⁶⁰₂₄ + ?

1. He⁴₂
2.  
3. e⁰_–1
4. β⁰₁

Answers

1. d.   The question gives the definition of half-life.
2. a.   Alpha particles give off the least penetrating radiation.
3. b.   In 70 years, there will be × 5.0 = 2.5 g. In 70 more years (140 total), there will be × 2.5 =1.25 g.
4. b.   Giving off an alpha particle is equivalent to giving off a helium nucleus. A²¹⁰₈₃ – He⁴₂ = B²⁰⁶₈₁
5. a.   When a beta particle is given off, the nucleus has the same mass number, but the atomic number is greater by one since a neutron is converted to a proton and an electron.
6. d.   A beta particle allows the mass to remain the same and increases the atomic number by 1.
7. b.   Gamma rays are not particles and therefore do not change the atomic number or atomic mass.