AP Physics 2 Questions on Alpha, Beta, and Gamma Decay

📚 Quick Study Guide

• ☢️ Alpha Decay: Emission of an alpha particle ($\ce{^4_2He}$), reducing the atomic number by 2 and mass number by 4.
• 📉 Beta Decay: Conversion of a neutron to a proton ($\ce{^0_{-1}e}$ emission or $\beta^-$ decay) or a proton to a neutron ($\ce{^0_{+1}e}$ emission or $\beta^+$ decay), changing the atomic number by 1 (either increasing or decreasing) and keeping the mass number constant.
• ✨ Gamma Decay: Emission of a high-energy photon ($\gamma$) from the nucleus, with no change in atomic number or mass number.
• ⏱️ Half-life: The time required for half of the radioactive nuclei in a sample to decay.
• ⚛️ Decay Equation: General form: $\ce{^A_ZX -> ^{A'}Z'Y + particle}$, where A is the mass number, Z is the atomic number, X is the parent nucleus, and Y is the daughter nucleus.
• 🧮 Balancing Equations: Mass number and atomic number must be conserved on both sides of the equation.

🧪 Practice Quiz

1. What type of decay involves the emission of a helium nucleus?
   1. Alpha Decay
   2. Beta Decay
   3. Gamma Decay
   4. Positron Emission
2. During beta-minus decay, what changes occur in the nucleus?
   1. A proton converts into a neutron.
   2. A neutron converts into a proton.
   3. The number of neutrons remains the same.
   4. The number of protons decreases.
3. Which type of decay does NOT result in a change in the atomic number of the nucleus?
   1. Alpha Decay
   2. Beta Decay
   3. Gamma Decay
   4. All of the above
4. What particle is emitted during gamma decay?
   1. Electron
   2. Proton
   3. Photon
   4. Neutron
5. A nucleus undergoes alpha decay. If the original nucleus was $\ce{^{238}_{92}U}$, what is the resulting nucleus?
   1. $\ce{^{234}_{90}Th}$
   2. $\ce{^{238}_{91}Pa}$
   3. $\ce{^{234}_{92}U}$
   4. $\ce{^{236}_{90}Th}$
6. Which of the following best describes beta plus decay?
   1. Emission of an electron.
   2. Emission of a positron.
   3. Emission of a helium nucleus.
   4. Emission of a photon.
7. The half-life of a radioactive isotope is 10 years. If you start with 1000 atoms, how many atoms will remain after 20 years?
   1. 500
   2. 250
   3. 125
   4. 0