As big as a house, will that be enough? I hold my magnifying glass up … and it's very interesting … but … no atoms … So, on to Setting Number 3 …. I turn the dial to setting Number 2 … Now the pea grows again, until it's the size of a house. Will that be enough? I take my magnifying glass and look carefully at the surface but … no … as big as a beach ball is not enough … So…. I usually make a 'shaggy dog story' out of this example, by pretending to have a Hollywood-style 'Matter-expander' and powerful magnifying class.: 'Okay … I turn the Expander Dial up to Position 1, and the pea grows to the size of beach ball. How large would the pea have to be, before we could see the atoms? Learners however may assume that the properties of the bulk materials are due to the particles having those properties – so students may suggest that, for example, that some particles are softer than others or that in a sponge, the particles are spread out more, so it can absorb more water.Ī good way to get over to students the incredibly tinyness of atoms, is to use this example: suppose we wanted to see the atoms in a frozen pea, and could somehow magically expand the pea (by expanding all its constitutent atoms). are emergent properties that results from enormous numbers of molecule-scale 'particles' (or ' quanticles') that themselves have quite different behaviour individually. This becomes important later because much of chemistry supposes that many of the characteristics of substances as observed in the lab. Bill did not make this error, as later in the interview he told me that 'the kind of specks of dust, has lots of particles in it, to make up the shape of it'. Students have no real basis on which to understand the scale of atoms and molecules, and often assume they are particles much like the specks and grains that can just be seen. These entities are usually much too small to be see with an optical light scope (although other instruments such as scanning tunnelling 'microscopes' provide images showing electric potential profiles that can be interpreted as indicating individual atoms). The term 'particle' used in introductory science classes is often used generically to cover atoms, molecules and ion. They move a very tiny amount, but we can't see that … because they are microscopic. Tell me the bit about the solids again? Tell me what you said about the particles in the solids? Later in the interview, Bill used the term microscopic to describe the particles in a solid, where a scientist would describe them as 'submicroscopic' (or 'nanoscopic'): He considered they were too small to be seem with a magnifying glass, but large enough to probably be seen with a microscope.īill, like a good scientist, qualified this answer as he had not actually undertaken the necessary observation to confirm this: but his intuition seemed to be that these particles could not be so small that they would not be visible through a microscope. He seemed to be convinced of their existence, despite not being able to see them. However, I continued, accepting Bill's suggestion of a table being solid as a reasonable example.īill knew that the particles in a solid were very tiny. From a chemical perspective a table is not solid. Technically the terms solid, liquid and gas refer to samples of substances and not objects. Well, solids they stay same shape and their particles only move a tiny bitĮrm, they're the bits that make it what it is, I think. So how do you know if something is a solid, a liquid or a gas? Bill was explaining that he had been learning about the states of matter, and introduced the notion of there being particles: Taber Image by 2427999 from Pixabayīill was a participant in the Understanding Science Project.

Solid particles