Elements and Performance Criteria

RANGE STATEMENT
The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.
Codes of practice/standards
Where reference is made to industry codes of practice, and/or Australian/international standards, it is expected the latest version will be used.
Context
This competency applies to metallurgical technicians who are responsible for determining the chemical composition of materials, products and work in progress and making recommendations as to what needs to be done to produce the required product.
The unit is intended to complement other more specific metallurgy units by providing general chemical knowledge.
Physical properties of crystalline solids
Crystalline solids include molecular, metallic, ionic, extended covalent solids. Physical properties include but are not limited to - boiling point, melting point, solubility in polar and/or non-polar solvents, conductivity, ductility, brittleness, hardness.
Key properties
The key properties of metals in terms of their position on the Periodic Table are:
electrical conductivity
ionisation energy
atomic radius
melting point
boiling point
combining power (valency)
electronegativity
reactivity
Use of formulae
Formulae will be correctly written for given compounds and correct names will be written from given formulae
Definitions of acids and bases
Arrhenius definition
Brønsted-Lowry definition
Strong Acid
Strong acids are those that have high degrees of dissociation yielding hydrogen ions
Weak acids
Weak acids have partial dissociation of hydrogen ions and exist mostly in the associated form.
Strong bases
Strong bases completely or almost completely dissociate into hydroxide ions and a conjugate acid.
Weak bases
Weak bases partially dissociate into hydroxide ions and a conjugate acid.
Stoichiometry
The calculation of the quantities of chemical elements or compounds involved in a chemical reaction.

EVIDENCE GUIDE
The Evidence Guide provides advice on assessment and must be read in conjunction with the Performance Criteria, Required Skills and Knowledge, the Range Statement and the Assessment Guidelines for the Training Package.

Overview of assessment
This competency also requires evidence of competency in the description of chemical laws, principles and terminology. The application of the chemical laws and principles to a selection of appropriate scenarios should also be required. The scenarios may be drawn directly from the workplace or may be simulated case studies.
Critical aspects for assessment and evidence required to demonstrate competency in this unit
It is essential that competence is demonstrated in the ability to:
describe elements and compounds according to their chemical properties
use recognised and appropriate chemical symbols and terminology
Consistent performance should be demonstrated. In particular look to see that:
a wide variety of elements and compounds can be described
the application of chemical laws and reactions to non laboratory situations can be explained
Relationship to other units
This unit may be assessed concurrently with other relevant units.

Assessment method and context
Assessors must be satisfied that the person can consistently perform the unit as a whole, as defined by the Elements, Performance Criteria and skills and knowledge. The unit is suitable for assessment in conjunction with other metallurgy units and a holistic approach should be taken to the assessment wherever possible.
Competence in this unit may be assessed:
in a workplace
in a suitable laboratory facility,
by use of a suitable simulation and/or a range of case studies/scenarios
by a combination of these techniques.
Resource implications
This section should be read in conjunction with the range of variables for this unit of competency. No special resources are required. However resources may be required where holistic assessment with other units is undertaken including suitable access to an operating plant or equipment that allows for appropriate and realistic simulation. A bank of case studies/scenarios and questions will also be required to the extent that they form part of the assessment method. Questioning may take place either in the workplace, or in an adjacent, quiet facility such as an office or lunchroom. No other special resources are required.