Misconception 1
All materials can be classified as a solid, liquid or gas. (Department of Education and
Training, 2015).
About
Research suggests conceptual understandings of solids, liquids and gases are shaped early on through everyday
interactions and language appears to strongly influence their identification of each state (for eg. students identify
solids as being able to be held, liquids as runny and gases like air (Australian Science Teachers Association, 2013).
These experiences create the misconception that matter can only exist or have properties of one form and are
easily categorised (Jones, 1984 & Krnel, Watson & Glazar, 1998).
McGuigan, Qualter & Schilling (1993) says when identifying a liquid, students generally select options such as
water, milk, and other water based solutions. McGuigan et al (1993) says rarely students identify non-water based
liquids such as oil, paints, or detergent and generally relate liquid to water and or that all liquids contain water.
This misconception is complicated by the belief solids must be hard, substances such as powder or a sand are a
liquid as they can be poured or that powder is solid because it does not ‘wet’ (McGuigan, Qualter & Schilling, 1993,
Krnel, Watson & Glazar, 1998).
Scientific view
Human nature encourages categorising. It is easy to see how this misconception occurs as a result of students’ life
experience. Kyle, Family, & Shymansky (1989) says these notions need to be challenged by giving encountering
experiences which challenge these perceptions. The three levels of classification (solids, liquids and gas) are
mandated by the year 5 level curriculum and provide a convenient framework. However, many materials make
classification troubling such as powder, toothpaste, the human body, gel, goo, dry ice, dripping icy poles, a soft
drink can, candle wax, mayonnaise and so on. The Department of Education and Training (2014) provides
principles to assist with the classification which can be found here. Classification is further hindered by substances
which change states depending on factors such as temperature, pressure or multiple states such as chocolate,
butter and immersions (Department of Education and Training, 2014).
Links to the Australian Curriculum (ACARA, 2015)
Year Level
Year 5
Content Description
Science Understanding (Chemical Science)

Solids, liquids and gases have different observable properties and behave in
different ways (ACSSU077)

recognising that substances exist in different states depending on the
temperature

observing that gases have mass and take up space, demonstrated by using
balloons or bubbles
Elaborations

exploring the way solids, liquids and gases change under different situations
such as heating and cooling

recognising that not all substances can be easily classified on the basis of their
observable properties
Teaching Strategies and Suggestions
Critical teaching ideas
0. Classifying similar characteristics
1. Solids, liquids and gases are the overarching categories however some materials and substances do not
clearly fit within these parameters
2. Sometimes multiple classifications can be applied
3. Classification can be affected by multiple factors
NOTE: Students have extensive prior knowledge from the Chemical Science strand of the Australian Curriculum
(2015) on states of matter, the effects of temperature and physical and chemical change.
Engage
4. Class jigsaw: split into three groups with a pen and butcher paper labelled ‘what is a solid’, ‘what is a
liquid’ and ‘what is a gas’. Each group must brainstorm and then regroup to present findings and record
results. This will inform the teaching process for what they do and don’t know (Australian Science
Teachers Association, 2013).
Explore
5. Use POE (predict, observe and explain) chart. Produce a mystery bag containing solids, liquids and gasses. Fill
out prediction column. Hand items around then complete observation. Use elbow partners to build
understandings and discuss observable features. Include easily identifiable items as well as tricky ones. Discuss
results as a class and complete the explain column. Click below to print posters for sorting. The
misconception is challenged by sorting items into the categories including items which don’t obviously
belong anywhere (Australian Science Teachers Association, 2013). (Idea sourced from
http://scienceweb.asta.edu.au/years-5-6/unit1/lesson-one/yr56-unit1-lesson-1.html)
6.
Conduct an investigation on the life cycle of a snowman to investigate the physical
change of water (ice, water then to gas). Using a snowman provides a real life example.
Classify the snowman by creating a hypothesis, making predictions, taking scientific
observations throughout the day including the state of matter, create a conclusion
explaining what happened and why. Activity information and instructions:
http://www.frugalteacher.com/2011/09/life-cycle-of-snowman.html. Reinforce
investigation by watching the video on solids, liquids and gases:
https://youtu.be/jd0RXHfIKJQ. Discuss the effects of temperature on matter and how it
affects the state. Discuss whether water is a solid, liquid or gas. Draw a diagram. This task demonstrates
how temperature makes classification difficult thus negating the misconception (The Association for
Science Education, 2008).
7. Create slime: http://scienceweb.asta.edu.au/years-5-6/unit1/lesson-five/yr56-unit1-lesson-five.html and
complete the investigation attached explaining the behaviour of pressure or force and its state. What kind
of change has it undergone? This task demonstrates how pressure makes classification difficult thus
negating the misconception (The Association for Science Education, 2008).
Explain
8. Work though ‘What the world is made of’ (whole class, small groups or individually) covering states of
matter and changes to the state of matter: http://www.scootle.edu.au/ec/viewing/L3249/index.html
(Scootle, 2015). This challenges the misconception and provides extra information in a real life context.
Elaborate
9. Download the poster, display and use to conduct a simulation role play where
students move like a molecule. Provide examples which cannot simply be
classified as a solid, liquid or gas. Students pick one and draw a diagram as well as
explain everything they can about the classification process and why it is difficult.
https://s-media-cacheak0.pinimg.com/736x/b7/f0/aa/b7f0aa9a0d0cb79cc7fa066cc12da301.jpg
Evaluate


Students choose a format (written, typed, recorded etc) to define a solid, liquid and a gas. Provide 3
examples of materials or substances which are hard to classify and why. Finally what factors can influence
classification (temperature, force, physical change or chemical change).
Students select one object/material/substance and create a presentation on how to classify it, the
difficulty with classifying and determining the factors.