AS91172 Atomic and Nuclear Physics Study Guide

Standard Reference: AS91172.
Title: Demonstrate understanding of atomic and nuclear physics.
NQF Level: 2.
Credits: 3.
Source Credit: No Brain Too Small PHYSICS.
Assessment Status: Prior to 2012, this was an external standard. From 2012 onwards, it is likely to be assessed using an internal test, though teachers have the discretion to select from a range of assessment techniques.
Historical Context: This achievement standard replaced standard AS90256.
Permitted Responses: Responses must include written statements containing mathematical solutions and/or descriptions. Descriptions are allowed to include graphs or diagrams.

Achievement:
- Requires demonstrating understanding of atomic and nuclear physics.
- Involves writing statements that show an awareness of how simple facets of phenomena, concepts, or principles relate to a described situation.
Achievement with Merit:
- Requires demonstrating in-depth understanding of atomic and nuclear physics.
- Involves writing statements that give reasons why phenomena, concepts, or principles relate to a described situation.
- For mathematical solutions, the information provided may not be immediately obvious or directly usable, requiring further interpretation or derivation.
Achievement with Excellence:
- Requires demonstrating comprehensive understanding of atomic and nuclear physics.
- Involves writing statements that demonstrate an understanding of the connections between various concepts.

Thomson’s Plum Pudding Model:
- The model of the atom proposed by J.J. Thomson prior to the discovery of the nucleus.
Rutherford’s Gold Foil Experiment:
- The landmark experiment involving the firing of particles at thin gold foil which led to the discovery of the atomic nucleus.
Rutherford’s Model of the Atom:
- The planetary-style model resulting from the gold foil experiment findings, identifying a small, dense, positively charged nucleus.

Conservation Laws:
- Atomic number MUST be conserved in all nuclear reactions.
- Mass number MUST be conserved in all alpha, beta, and gamma emission reactions.
Radiation and Particle Types:
- Alpha ( $\alpha$ ) particles.
- Beta ( $\beta$ ) particles.
- Gamma ( $\gamma$ ) rays.
- Neutrons.
- Protons.
Properties of $\alpha$ , $\beta$ , and $\gamma$ Radiation:
- Ionising Ability: The capacity of the radiation to remove electrons from atoms to create ions.
- Penetrating Ability: The distance or type of material the radiation can pass through before being stopped.
- Behaviour in a Magnetic Field: How the path of the radiation is deflected (or not) when passing through a magnetic field, based on its charge.

Radioactive Decay: The process by which an unstable atomic nucleus loses energy by radiation.
Half-life: The time required for the amount of a radioactive substance to reduce to half of its initial value.
Decay Curves: Graphical representations showing the exponential decrease of radioactive nuclei over time.
Carbon Dating: A technique used to determine the age of an object containing organic material by using the properties of radiocarbon.

Fission Reactions: The splitting of a heavy nucleus into lighter nuclei, accompanied by the release of energy.
Fusion Reactions: The process where two light atomic nuclei combine to form a heavier nucleus, releasing energy.
Power Generation: The practical application of nuclear reactions to produce electricity.

Scientific Skills:
- The appropriate use of significant figures in all calculations.
- The appropriate use of units for all physical quantities.
- Use of notation: Both negative index notation (e.g., $ms^{-2}$ ) and slash notation (e.g., $m/s^2$ ) are acceptable.
Relationships and Formulae:
- Formulae listed in the achievement standard will be provided during assessment.
- Energy-Mass Equivalence: $E = mc^2$
- Power-Energy Relationship: $P = \frac{E}{t}$