Topic 4 – The atom: Putting it all together


In the last few posts, the atomic nature of the universe was discussed, Dalton’s atomic theory explained and we took a tour of the “guts” of an atom.  Now let’s use all this to understand how the pieces fit together to illustrate what makes the element (and atom) hydrogen, different from carbon, oxygen and neodymium.  The short story is the way the parts come together – it’s really a counting game.


This links to a periodic table you can download.

A new element is discovered almost every year – but for now, a current periodic table will show 118 unique elements.  (I’ve linked this image to a good table you can print out if you wish.)   All periodic tables will have at least 3 pieces of information.  For each element, every table should give you at least the symbol, the atomic mass and the atomic number.  Some have far too much information, stuff you should be able to infer from the position on the table, they symbol, the mass, and so on, but every table – except the ones on the shoes at the top of this post – should give the three fundamental data.  Of these three, the most important is the atomic number.  So important is the atomic number, notice it provides the organizing principle for the arrangement of the atoms.   Continue reading


Topic 1 – The Atomic Nature of the Physical Universe

An atom with its orbitals showingIf you take a moment to look around you, it’s a gorgeous world.  Every single thing you see that is solid has a shape, and the liquids and gases swirl and wave in ways that are wonderful to watch.  The macroscopic world is not only beautiful but it is functional.  The shapes, sizes and colors have function and meaning and in most cases, purpose.

But even the young school children know something like a tree is not one solid piece.  There are at the very least, bark, leaves and branches.  Right now if you look around wherever you are, you will probably easily notice that most things are made of pieces.  As I write, I am at my desk and in front of me I see pens, my computer screens and a couple of speakers.  The pens have caps and clips and I know inside I will find a thin pipe and inside that I will find ink.  The screens have a variety of plastic pieces all with different purpose and I know there are circuit boards and wires inside.  The speaker has a variety of buttons and knobs and the different kinds of materials are obvious.  Without really thinking about it, we see a pen, a screen and a speaker – the whole – but upon closer inspection, most things can be decomposed into parts.   Continue reading