{"id":4422,"date":"2018-01-10T20:24:51","date_gmt":"2018-01-11T03:24:51","guid":{"rendered":"https:\/\/blogs.ubc.ca\/stem2018\/?p=4422"},"modified":"2018-01-10T20:24:51","modified_gmt":"2018-01-11T03:24:51","slug":"does-gas-have-mass","status":"publish","type":"post","link":"https:\/\/blogs.ubc.ca\/stem2018\/2018\/01\/10\/does-gas-have-mass\/","title":{"rendered":"Does gas have mass?"},"content":{"rendered":"

In 1968, David Ausubel wrote \u201cThe most important single factor influencing learning is what the learner already knows. Ascertain this and teach him accordingly.\u201d (Ausubel, 1968, p. vi).\u00a0 Unlike an earlier idea that learner are blank slates that need to be filled by the teacher, more recently, the Personal Construct Theory recognizes that the person is a meaning-make, capable being an active participant in their learning, and of making judgements about their interpretations of evidences (Shapiro, 1988). \u00a0\u00a0If students enter a topic or concept with various misconceptions or alternative frameworks, this will negatively influence both their ability and willingness to incorporate new understandings.\u00a0 In science, this is quite prevalent, perhaps because we first use simple analogies to explain a concept and then elaborate more fully later, or perhaps the nature of science allows children to make their own observations and interpretations first.\u00a0 Whatever the reason, many students have misconceptions about various aspects of science.\u00a0 For example, many of my Bio11 students believe penguins have fur not feathers!<\/p>\n

I have chosen to work with the misconception that gases don\u2019t have mass, or even have a negative mass.\u00a0 This common misconception is likely due to students observations that adding more gas to a helium balloon causes it to float higher (Mayer, 2011), or trapping air bubbles under a toy in the bathtub allows it to float instead of sinking.\u00a0 According to Mayer, (2011), even after students performed an experiment in a sealed flask demonstrating that the mass doesn\u2019t change when a substance (iodine) goes from a solid to a gas, the majority still stuck to their false preconceptions and assumed they must have made an error in the experiment.\u00a0 This lead Mayer to recognize that preconceptions are very difficult to remove (Mayer, 2011).\u00a0 This phenomenon was also seen in the video clip about Heather and how she continued to stick to her theories about the strange curlicue orbit of earth and how light bounces to give indirect light.<\/p>\n

So what do we do about these misconceptions.\u00a0 Elliot (2016) notes that teachers who are aware of common misconceptions among their students were more effective, and that the common teacher approaches of avoiding students\u2019 existing beliefs altogether or telling students clearly they are wrong and that they need to think differently are ineffective.\u00a0 Posner et al (1982) view learning as a \u201cprocess of conceptual change\u201d where accommodation of misconceptions is needed to reorganize their current beliefs.\u00a0 For accommodation to occur, learners need to be dissatisfied with their current idea or model, and the new model must be rational, intelligible, plausible, and fruitful for further research (Posner et al., 1982).\u00a0 Teachers can use anomalies to point out limitations of misconceptions, thereby bringing the cognitive conflict (dissatisfaction) that drives new understandings (Elliot, 2016, Posner et al., 1982).\u00a0 I would suggest that using technology is a good way to do this for many abstract concepts.\u00a0 There are many online simulations (for example PhET) that enable learners to view the concepts, play with them, and visualize the greater explanatory ability of the scientific idea such as the states of matter and properties of gases (https:\/\/phet.colorado.edu\/en\/simulation\/states-of-matter<\/a>).<\/p>\n