Lesson 6.2 Balancing Nuclear Equations Chem GC Edition (1)

1. Introduction

  • Update on missing individual (referred to as "pineapple")

  • Focus on the review of nuclear reactions and radioactive decay

2. Types of Nuclear Reactions

2.1 Review of Radioactive Decay Types

  • Discussion of types of nuclear decay and related particles produced

  • Focus on understanding the remnants after specific types of radioactive decay

2.2 Alpha Decay

  • Definition: Alpha decay is the release of an alpha particle, which is essentially a helium nucleus (2 protons and 2 neutrons).

    • Notation: Helium can be written as ( \text{He}^{4}_{2} ) or denoted by the Greek letter alpha (( \alpha )).

  • Example Reaction:

    • Uranium-238 undergoes alpha decay, producing Thorium and an alpha particle.

    • Representation: [ \text{U}^{238}{92} \rightarrow \text{Th}^{234}{90} + \text{He}^{4}_{2} ]

  • Characteristics:

    • Primarily occurs with very large nuclei (certainly more than element 70).

    • Alpha particles have low penetrating power and can be stopped by skin.

3. Beta Decay

  • Definition: Beta decay is when a beta particle (an electron) is emitted.

    • Notation: ( \text{e}^{-} ) with a mass number of 0 and atomic number of -1.

  • Mechanism:

    • Neutron converts to a proton, increasing atomic number without changing the mass number.

  • Example:

    • Thorium undergoing beta decay converts to Protactinium with beta emission.

    • Representation: [ \text{Th}^{234}{90} \rightarrow \text{Pa}^{234}{91} + \text{e}^{-} ]

  • Characteristics:

    • Moderate penetration power, needing metal foil to shield against.

4. Gamma Radiation

  • Definition: Gamma rays are high-energy photons released during other decay processes.

    • Notation: ( \gamma )

  • Characteristics:

    • Extremely powerful and able to penetrate thick materials.

    • Important to shield against using lead or concrete.

    • Commonly emitted in conjunction with alpha and beta decays.

5. Other Types of Decay

5.1 Positron Emission

  • Definition: The emission of a positron (the antimatter counterpart of an electron).

    • Notation: ( \text{e}^{+} ) with mass number 0 and atomic number +1.

  • Mechanism: Converts a proton into a neutron.

  • Example:

    • Sodium undergoing positron emission producing Neon.

5.2 Electron Capture

  • Definition: The nucleus captures an inner orbital electron, converting a proton to a neutron.

  • Characteristics:

    • Results in the emission of gamma radiation but no change in mass number.

6. Balancing Nuclear Reactions

  • Explanation of balancing as a method to predict particles produced in decay.

  • Conservation of Mass: The total mass number and atomic numbers must equal on both sides of the equation.

  • Example: Nuclear fission of Uranium-235:

    • Process: Organizations equation showing how uranium splits when bombarded with a neutron.

    • Resulting elements and neutrons must be calculated to ensure equal mass and atomic numbers.

7. Safety Precautions in Nuclear Reactions

  • Nuclear power plants often use lead shielding and thick walls to prevent radiation exposure.

  • Importance of understanding the different types of radiation when considering nuclear safety.