Dojo radioactivity

• What are isotopes?

  Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
• Give an example of isotopes of carbon.

  Carbon-12, carbon-13, and carbon-14 are isotopes of carbon.
• What do isotopes have in common regarding their chemical properties?

  Isotopes have identical chemical properties.
• What is nuclear binding energy?

  Nuclear binding energy is the energy required to break a nucleus into its constituent protons and neutrons.
• What is mass defect?

  Mass defect is the difference between the mass of a nucleus and the sum of the masses of its constituent nucleons.
• Write the formula for mass defect.

  $\Delta m =$$Z m_p +$$N m_n - m_{nucleus}$
• What do the variables in the mass defect formula represent?

  $Z$ is the number of protons, $N$ is the number of neutrons, $m_p$ is the mass of a proton, $m_n$ is the mass of a neutron, and $m_{nucleus}$ is the mass of the nucleus.
• How is binding energy calculated using mass defect?

  $E_B =$$\Delta m c^2$
• What is the binding energy of helium-4?

  The binding energy of helium-4 is 28.3 MeV.
• What does binding energy per nucleon indicate?

  Binding energy per nucleon indicates nuclear stability.
• Write the formula for binding energy per nucleon.

  $\text{Binding Energy per Nucleon} =$$\frac{E_B}{A}$
• Why does the binding energy per nucleon curve peak around iron (Fe-56)?

  The peak explains why fusion releases energy for light elements and fission releases energy for heavy elements.
• What is the strong nuclear force?

  The strong nuclear force is the fundamental force responsible for holding quarks together to form hadrons and binding protons and neutrons in atomic nuclei.
• What are the key characteristics of the strong nuclear force?

  The strong nuclear force is extremely strong at short ranges, rapidly decreases with distance, and overcomes electromagnetic repulsion between protons.
• How much stronger is the strong nuclear force compared to the electromagnetic force at nuclear distances?

  The strong nuclear force is about 100 times stronger than the electromagnetic force at nuclear distances.
• What evidence supports the existence of the strong nuclear force?

  Evidence includes the stability of nuclei, binding energy measurements, and scattering experiments.
• How does the neutron to proton ratio affect nuclear stability?

  The stability of nuclei depends on the ratio of neutrons to protons, with light elements needing roughly equal numbers and heavier elements needing more neutrons than protons.
• What is a common mistake regarding neutron to proton ratios in nuclei?

  A common mistake is thinking that all nuclei with equal numbers of protons and neutrons are stable.
• What happens to the binding energy per nucleon for nuclei with mass numbers greater than about 60?

  The binding energy per nucleon remains relatively constant at around 8.5-8.8 MeV.
• What is radioactive decay?

  Radioactive decay is a spontaneous process where unstable atomic nuclei emit radiation to achieve a more stable configuration.
• What is a key characteristic of individual decay events in radioactive decay?

  Individual decay events are unpredictable.
• How does the probability of decay behave over time?

  The probability of decay is constant over time.
• What can be said about the behavior of large numbers of radioactive atoms?

  Large numbers of atoms follow statistical patterns.
• What is alpha decay?

  In alpha decay, a nucleus emits an alpha particle, which is equivalent to a helium-4 nucleus.
• Write the general equation for alpha decay.

  $^A_Z X \rightarrow ^{A-4}_{Z-2} Y +$$^4_2 He$
• Provide an example of alpha decay.

  Uranium-238 decaying to Thorium-234: $^{238}_{92} U \rightarrow ^{234}_{90} Th +$$^4_2 He$
• What are the two forms of beta decay?

  Beta decay comes in two forms: Beta-minus and Beta-plus.
• Describe beta-minus decay.

  In beta-minus decay, a neutron converts to a proton, emitting an electron and an antineutrino.
• Describe beta-plus decay.

  In beta-plus decay, a proton converts to a neutron, emitting a positron and a neutrino.
• Write the general equations for beta decay.

  Beta-minus: $^A_Z X \rightarrow ^A_{Z+1} Y +$$e^- +$$\bar{\nu}_e$; Beta-plus: $^A_Z X \rightarrow ^A_{Z-1} Y +$$e^+$$+$$\nu_e$
• Provide an example of beta-minus decay.

  Carbon-14 undergoing beta-minus decay: $^{14}_6 C \rightarrow ^{14}_7 N +$$e^- +$$\bar{\nu}_e$
• What is gamma decay?

  Gamma decay involves the emission of high-energy photons (gamma rays) from an excited nucleus.
• Write the general equation for gamma decay.

  $^A_Z X^*$$\rightarrow ^A_Z X +$$\gamma$
• What are neutrinos and antineutrinos?

  Neutrinos and antineutrinos are nearly massless, neutral particles emitted in beta decay.
• Why were neutrinos proposed?

  Neutrinos were proposed to explain the continuous energy spectrum of beta particles.
• How do neutrinos interact with matter?

  Neutrinos interact very weakly with matter, making them extremely difficult to detect.
• What are the penetrating and ionizing abilities of alpha radiation?

  Alpha radiation is the least penetrating but most ionizing.
• How do beta and gamma radiation compare in terms of penetration and ionization?

  Beta radiation has moderate penetration and ionization, while gamma radiation is the most penetrating but least ionizing.
• What is activity in the context of radioactive decay?

  Activity (A) is the rate of decay, measured in becquerels (Bq).
• What is the relationship between count rate and activity?

  Count rate is the number of decay events detected per unit time and is always less than or equal to the activity.