8.1 Radioactivity

• Radioactivity occurs from unstable atomic nuclei as they transition to more stable configurations
• What particle is emitted during alpha decay?

  Helium nucleus
• What is the particle emitted during beta decay called?

  Beta particle
• What happens to the mass number during beta decay?

  Remains unchanged
• What is an example equation for beta+ decay?

  ^{22}_{11}Na \rightarrow ^{22}_{10}Ne + e^+</latex>
• Gamma decay changes the atomic number of the nucleus.

  False
• What particle is emitted during alpha decay?

  Helium nucleus
• Radioactivity occurs spontaneously without external intervention.

  True
• What is the composition of an alpha particle?

  Two protons and two neutrons
• During beta decay, what happens to the mass number of the nucleus?

  Remains unchanged
• In a balanced nuclear equation, the atomic number and mass number must be conserved.

  True
• What is the emitted particle in alpha decay?

  Alpha particle
• Which particle is emitted in beta- decay?

  Electron
• The decay constant is the probability per unit time that a radioactive nucleus will decay
• What is the definition of radioactivity?

  Spontaneous emission of radiation
• Which type of decay has the highest ionizing power?

  Alpha decay
• Beta decay involves the emission of an electron or positron.


  True
• Alpha decay involves the emission of a particle with two protons and two neutrons
• Match the type of decay with its emitted particle:

  Alpha decay ↔️ Helium nucleus

  Beta decay ↔️ Electron or positron

  Gamma decay ↔️ High-energy photon
• Arrange the nuclear equations in the order they represent alpha, beta, and gamma decay:

  1️⃣ ^{238}_{92}U \rightarrow ^{234}_{90}Th + ^{4}_{2}He</latex>

  2️⃣ $^{14}_{6}C \rightarrow ^{14}_{7}N +$$e^ -$

  3️⃣ $^{60}_{27}Co^ *$$\rightarrow ^{60}_{27}Co +$$\gamma$
• Match the type of decay with its range in air:

  Alpha decay ↔️ Few centimeters

  Beta decay ↔️ Few meters

  Gamma decay ↔️ Long distances
• Arrange the steps for writing a balanced nuclear equation:

  1️⃣ Parent nucleus → Daughter nucleus + Emitted particle

  2️⃣ Ensure atomic number is conserved

  3️⃣ Ensure mass number is conserved
• In gamma decay, the atomic number and mass number remain the same.


  True
• What type of particle is emitted during gamma decay?

  $\gamma$
• During beta decay, a positron has a positive electric charge
• The activity of a radioactive substance is measured in Becquerels or Curies
• Radioactivity is a process that requires external intervention.

  False
• During alpha decay, the atomic number decreases by two
• Gamma decay involves the emission of a high-energy photon
• During gamma decay, the atomic number and mass number remain
• What type of decay is illustrated by the example \( ^{238}_{92}U \rightarrow ^{234}_{90}Th + ^{4}_{2}He \)?

  Alpha decay
• What happens to the atomic number and mass number during alpha decay?

  Atomic number -2, mass number -4
• The penetrating power of alpha particles is low
• Match the type of decay with its description:

  Alpha decay ↔️ Emission of a helium nucleus

  Beta decay ↔️ Emission of an electron or positron

  Gamma decay ↔️ Emission of a high-energy photon
• Order the types of radioactive decay from highest to lowest penetrating power:

  1️⃣ Gamma decay

  2️⃣ Beta decay

  3️⃣ Alpha decay
• The range of gamma particles in air is very long
• Order the types of decay based on their balanced nuclear equation format:

  1️⃣ Alpha decay

  2️⃣ Beta decay

  3️⃣ Gamma decay
• Beta decay can result in either the emission of an electron or a positron.


  True
• What type of law does radioactive decay follow?

  Exponential law
• Match the type of radioactive decay with its description:

  Alpha decay ↔️ Emission of a helium nucleus

  Beta decay ↔️ Emission of an electron or positron

  Gamma decay ↔️ Emission of a high-energy photon