Chemistry, Particle Physics, Physics

Never Trust An Atom, They Make Up Everything… Right?

Atoms are all around us, they make up everything that you can see around you.

They can be thought of as the building blocks of the world, the things that you can touch: There is silicon in the glass in the vase next to me, and a vital part of all our electronics; iron in the wood burner; and carbon, oxygen and Hydrogen in pretty much everything (clothes, a wooden table, even myself!). All of these (silicon, iron, carbon, oxygen, hydrogen) are different elements, made up of slightly different atoms. 

That’s what you can say with some certainty, using only your senses, and a little bit of scientific knowledge that you were probably taught in Secondary School.  What if I told you that there was more to the Universe than that?

Definitions 
Elements are types of atoms that are distinguished by their proton number. They can not be broken down further chemically.
Protons are a positively charged particle in an atom's nucleus
Neutrons are particles found in the atom’s nucleus that have no charge
Electrons are tiny negatively charged particles that move around the nucleus
Radioactive Decay is when an unstable atomic nucleus releases radiation to reduce its energy.
Relevant Definitions to help your understanding

Never Trust An Atom… What is an Atom?

An atom consists of a nucleus made of protons and neutrons and tiny electrons that ‘orbit’ it. In real terms, this size difference is like the difference between a marble (as the nucleus) and a single grain of sand (as the electron)!

Marble in Sand representing the size difference between an atom’s nucleus and electrons

Despite their size, they are what gives an atom its size- if the whole atom was the size of a football stadium, the nucleus would only be the size of a fly, even though it is what makes up most of the mass! This is because….  an atom is actually 99.9% ‘empty’ space! But why do things feel solid then? It’s all down to the movement of electrons. The model of the atom you are typically taught at school isn’t actually the whole truth. It’s called the Bohr model, and was proposed over 100 years ago in 1913! It shows the atom with a large nucleus in the middle and concentric electron orbits. In fact, it is the same model as in Never Trust an Atom’s logo!

As you can see from the photos, the Bohr model is far easier to understand and draw, and requires far less physics knowledge, which is why you are taught it at school! It also has an easier name: Schrodinger-Heisenberg is quite a mouthful!

The updated model has electron orbitals instead of orbits. This is because the electrons don’t follow circular orbits, they move randomly, within an orbital area. The more energy they have, the faster they move. This creates the different energy levels- where the electron can go, which gives us the orbitals! The lowest energy electrons are closest to the nucleus, and those with higher energies are further away.


Another look at electron orbitals, showing the lowest energy level at the top (1s)

Electrons are especially important in creating compounds, as very few of the materials we see around us are pure elements. The electrons can be shared (used in covalent bonding) or given to make ions (ionic bonding creates metal-nonmetal compounds).

Protons, Neutrons and Electrons are just the beginning, however- if you want to find out more about the weird world of quantum and particle physics, you’ll love tomorrows post!

They Make Up Everything…

Although the number of electrons and neutrons in an atom can change to make either ions (loss or gain of electrons) or isotopes (due to extra or fewer neutrons, often as a result of radioactive decay); the number of protons in a stable atom does not. This proton or atomic number defines what type of atom it is! These different types of atoms are called elements and are ordered by proton number in the periodic table. There are 118 different elements but the most common are the lighter elements: the top three are Hydrogen (formed in the big bang and accounts for 74% of all normal ‘baryonic’ matter), Helium and Oxygen. This is because these elements, up to iron, are forged in the heart of stars. The other 92 elements are very rare, formed only in the violent deaths of stars- supernovae- or in the lab! Out of these 92, 24 are synthetic elements, primarily the actinides (that bottom layer of the extra bit of the periodic table)-elements 89 to 103- and the bottom row of the periodic table, elements 104-118! The final 4 elements are relatively new, so have only recently been given names: for a while, after their discovery, they were only given imaginative names like ununtrium, ununhexium or ununoctium which directly relates to their atomic number (try to figure out how many protons they have and put it in the comments!). These elements are highly radioactive, and only survive for a few seconds or less before decaying

Pi chart showing the chemical composition of the universe: Hydrogen (purple)= 74%, Helium (turquoise)= 24% and other (various colours)= 2%
Chemical Composition of the Universe

…Right?

However although atoms make up the tangible matter, the periodic table does not encompass everything in the universe. The particles within the atom can exist by themselves, as well as others also described in the standard model: this creates exotic particles like mesons and various heavy hadrons, not to mention the many different types of radiation!  And is this a good time to mention the fact that this doesn’t make up even 5% of our universe?

☆☆☆

If you can’t trust an atom… trust in science!

☆it’s like magic, but it’s true whether you believe in it or not!☆

See you next time!

☆☆☆

Suggested Post: Is the Standard Model falling apart?

Image Background: Purple Cosmic Web
Large, Curly font says Stay Curious
Smaller block font beneath in light purple filled box says And Remember: never trust an atom

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