P1.1 The particle model
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P1.1 The particle model:
Mathematical learning outcome:
PM1.1i recall and apply: density (kg/m3)= mass (kg)/volume (m3)
Assessable content statements:
P1.1a describe how and why the atomic model has changed over time
P1.1b describe the atom as a positively charged nucleus surrounded by negatively charged electrons, with the nuclear radius much smaller than that of the atom and with almost all of the mass in the nucleus
P1.1c recall the typical size (order of magnitude) of atoms and small molecules
P1.1d define density
P1.1e explain the differences in density between the different states of matter in terms of the arrangements of the atoms and molecules
P1.1f apply the relationship between density, mass and volume to changes where mass is conserved (M1a, M1b, M1c, M3c)
A clip just over 2 minutes in length summarising Thompson’s plum pudding model.
In the video in this model, the plums represent negatively charged electrons which can be ‘plucked’ out of the atom, leaving behind some positively charged pudding.
General template that learners can use to represent any historical figure.
This can be used for the scientists involved in the development of the atomic structure.
Approaches to teaching the content
The process behind the development of the atomic model, such as the gold foil experiment by Geiger and Marsden can be difficult for learners to grasp, as radioactivity is not covered in this topic. Animations of the gold foil experiment can help learners appreciate how the observations were interpreted to create the model.
Learners should have a basic understanding of the ways in which particles behave. The chapters in this topic build strongly on these foundations so it is advisable to check prior understanding before exploring the areas on density. Modelling is a good tool when representing particles in different states of matter. This should not be new to GCSE learners, but they have possibly not made the link at Key Stage 3 between densities and the arrangements between atoms in solids, liquids and gases. The story of Archimedes and calculating the density of the gold crown can be a good starting point for density. This area is best delivered through a range of practical sessions, which can include floating and sinking predictions which are linked to sub-topic P1.3.
Common misconceptions or difficulties learners may have
Learners may have some misconceptions about particles in different states of matter that need addressing before approaching the density chapter. This can be done through assessing learner’s starting points, modelling and scaffolding of responses.
Learners may also find the recall areas such as atom size difficult as a concept as they cannot be viewed. The suggested use of props and discussion of relative sizes may assist in this area.
Conceptual links to other areas of the specification – useful ways to approach this topic to set learners up for topics later in the course
Statement P1.1d links with P1.3h as learners can relate density to floating and sinking in practical investigations.
Numerous free videos and experiment sheets for density experiments that can be printed straight from the website and used for whole class practical activities.
Calculations can be completed based on many of the results.
Approaches to teaching the content
A definition for density can be explored using population density on a world map. Learners can quickly work out that an area of land is more densely populated if there are more people per m2 of land. This can then be broadened into a discussion about number of particles, their mass and volume using this analogy.
Applying the equation for density for conserved masses can be delivered practically such as with soil. The s mass of soil can be calculated however can be compressed to alter the volume, which will alter the density. Learners can make predictions based on their knowledge of this topic. These calculations can also be related to engineering e.g. foundation structures.
A research link for learners to find information about the development of the atomic model.
This can be used to make a timeline.
A second research link for learners to find information about the development of the atomic model.
This can be used to make a timeline or Facebook profiles to represent the information required.
Three levelled worksheets based on Geiger and Marsden’s experiments. They take the learners through the practical and the results and ask a range of questions to follow.
This is a good resource to use maybe as a consolidation of the topic once radiation has been looked at in more detail.
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