Core concepts
When exploring the natural world, the wide expanse of knowledge leads us to develop the big ideas or core concepts of science. Teachers and students can use these to explain and make predictions about a range of related phenomena in the natural world. Through the curriculum, these concepts are introduced and developed according to the age and stage of the students.
| The chemical and physical properties of substances are determined by their structure at a range of scales | Substances change and new substances are produced by rearranging atoms; these changes involve energy transfer and transformation | |
| F | Recognise that objects can be composed of different materials and describe the observable properties of those materials | Concept not covered at this year level |
| Y1 | Concept not covered at this year level | Concept not covered at this year level |
| Y2 | Concept not covered at this year level | Recognise that materials can be changed physically without changing their material composition and explore the effect of different actions on materials including bending, twisting, stretching and breaking into smaller pieces |
| Y3 | Investigate the observable properties of solids and liquids and how adding or removing heat energy leads to a change of state | Investigate the observable properties of solids and liquids and how adding or removing heat energy leads to a change of state |
| Y4 | Examine the properties of natural and made materials including fibres, metals, glass and plastics and consider how these properties influence their use | Concept not covered at this year level |
| Y5 | Explain observable properties of solids, liquids and gases by modelling the motion and arrangement of particles | Concept not covered at this year level |
| Y6 | Concept not covered at this year level | Compare reversible changes, including dissolving and changes of state, and irreversible changes, including cooking and rusting that produce new substances |
This section is about core concepts and alternative conceptions:
- The core concepts of science are framed by the six overarching ideas identified by ACARA.
- Addressing alternative conceptions in the core concepts requires teachers to plan discussions and investigations that allow students to question their prior assumptions and understanding of the core concepts and key ideas.
Chemical and physical properties
Alternative conceptions
The chemical and physical properties of substances are determined by their structure at a range of scales.
This list of alternative conceptions is not meant to be comprehensive, but instead aims to provide a starting point.
Alternative conception | Accepted conception |
| Humans make chemicals. | All matter is made of atoms and molecules (chemicals). |
| Air is weightless or has negative weight. | Air has mass and can be affected by gravity. Therefore, air has weight. |
| There is air between air particles/molecules. | There is empty space, not air between particles. |
| The particles in the air are not moving. | Air is made up of gas particles that are constantly moving (have kinetic energy). |
| The only gas we breathe out is carbon dioxide. | The air we breathe is 21% oxygen, 78% nitrogen (and small amounts of carbon dioxide, neon and hydrogen). We use approximately 3% of the oxygen we breathe in. This is why CPR works (18% oxygen in each breath out). |
| Liquids can be compressed. | Only gas can be compressed. |
| Gas means the gas we use in barbeques or cooking. | Gas is a state of matter where particles can fill any size or shape container. |
| A conductor is something that keeps things warm. | Conductors allow energy (heat and electricity) to be transferred. |
| Metals attract cold better than wooden objects. | Metals are good conductors of heat. Touching metal in a cold room will conduct the heat away from your body (making your hand feel cold). Wood does not conduct heat as well as metal. This keeps the heat in your hand (feels warmer than metal). |
| Atoms are solid spheres. | Atoms are made up of mostly space that contains sub-atomic particles (protons, neutrons, and electrons). |
| Atoms have the same properties as their bulk material. For example, iron atoms can melt. | Atoms have different properties than the bulk substance. |
| All liquids boil at 100 degrees Celsius. | All materials have different boiling points. |
| A hard material is strong. | Hardness is an inability to be scratched or deformed. Strength is the amount of force applied to a material before it breaks. |
This section is about core concepts and alternative conceptions:
- The core concepts of science are framed by the six overarching ideas identified by ACARA.
- Addressing alternative conceptions in the core concepts requires teachers to plan discussions and investigations that allow students to question their prior assumptions and understanding of the core concepts and key ideas.
Changing substances
Alternative conceptions
Substances change and new substances are produced by rearranging atoms; these changes involve energy transfer and transformation.
This list of alternative conceptions is not meant to be comprehensive, but instead aims to provide a starting point.
Alternative conception | Accepted conception |
| Heating a substance always means raising its temperature. | When a substance is undergoing a change in its state (ice to water), it does not immediately change its temperature. |
| Bubbles in boiling water contain air. | Bubbles in boiling water contain water vapour (gas form of water). |
| Steam is water gas | Steam is a very small collection of condensed liquid water suspended in the air. |
| Melting and dissolving are the same. | Melting is a change in state from solid to liquid. Dissolving occurs when a substance (solid) breaks into such small components that they cannot be seen in a solution. |
| Dissolved substances do not take up space. | The volume of water will change when salt is added. |
| When water in a container evaporates, the water has soaked into the container. | Liquid water evaporates and becomes water vapour in the air. |
| Boiling water makes steam which becomes clouds. | Liquid water evaporates and becomes water vapour in the air. As the water vapour cools, it condenses into small collections of liquid water (steam or clouds). |
| Cold water leaks through a glass of water making it wet on the outside. | Water vapour in the air condenses against the cold glass of water forming droplets. |
| An evaporated substance will become lighter if it turns into a gas. | Matter is conserved at all states and its mass does not change. |
| Chemical reactions are irreversible. | Some chemical reactions have an equilibrium where they can be reversed to achieve a balance. |
| Chemical reactions are caused by mixing substances. | Some chemical reactions require energy (usually in the form of heat) to be initiated. Other chemical reactions are spontaneous. |
| Energy is used up in a chemical reaction. | Energy and matter are always conserved in chemical reactions. |
| Matter disappears in a chemical reaction (i.e. fire). | Matter is always conserved in a chemical reaction. |
| Energy/heat/sound is a form of matter | Matter has mass and takes up space. Energy is a quantitative property of a system that can be transferred or transformed. |
| Atoms change during a chemical reaction. | Matter (atoms) are conserved. |
| Smoke is a gas. | Smoke is a combination of small solid particles (often carbon) suspended in the air. |
| The fuel all turns into smoke or carbon dioxide. | The general formula of combustion reactions is fuel + oxygen → carbon dioxide + water |
This section is about core concepts and alternative conceptions:
- The core concepts of science are framed by the six overarching ideas identified by ACARA.
- Addressing alternative conceptions in the core concepts requires teachers to plan discussions and investigations that allow students to question their prior assumptions and understanding of the core concepts and key ideas.