Sunday, February 22, 2009

Atoms – The Basics

Once again, I was watching a show on the Science Channel that was way over my head. This time it was about atoms. The whole show just blew my mind and much of the details were so hard to even comprehend. I would need to watch the episode about 10 more times to even have a chance of completely understanding. I'm not even going to get into the chemistry classes I took in high school and college–not good. I guess that's why I make pretty pictures for a living.

Atom - the basic unit of a chemical element.

The word atom is derived from the Greek word atom, which means indivisible. Atoms and cannot be chemically subdivided by ordinary means. Atoms are the basic building blocks of matter that make up every object. Matter has mass and takes up space. There are 90 naturally occurring kinds of atoms. Scientists have been able to make about 25 more.

Atoms are composed of three types of particles: Protons, Neutrons, and Electrons. Protons and Neutrons are responsible for the majority of the atomic mass as the mass of an Electron is very small.

Both the Protons and Neutrons reside in the Nucleus. Electrons reside in orbitals around the Nucleus.

Protons carry a positive charge.

Neutrons carry no charge.

Protons and Neutrons join together to form the Nucleus, the central part of the atom.

Electrons carry a negative charge and circle the nucleus. Electrons are bound to the nucleus by the electromagnetic force.

Atoms usually have about as many Neutrons as Protons. Atoms always have as many Electrons as Protons and are electrically neutral. If the Electrons and Protons are not the same in an atom, it has a positive or negative charge and is an Ion.

Ion - an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

It is the number of Protons that determines the atomic number on the Periodic Table. The number of Protons in an element is constant, but Neutron numbers may vary, so mass number (protons + neutrons) may vary. The number of Neutrons determines the Isotope of the element.

Hydrogen (#1 on the Periodic Table)
1 Proton
1 Electron
0 Neutrons

Helium (#2 on the Periodic Table)
2 Protons
2 Electrons
2 Neutrons

Adding a Proton makes a new kind of atom. Adding a Neutron makes an isotope of that atom–a heavier version of that atom.

Isotope – each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties. Some isotopes are radioactive, meaning they "radiate" energy as they decay to a more stable form, perhaps another element half-life (time required for half of the atoms of an element to decay into stable form).

In 1968, scientist discovered particles inside the Proton and Neutron. These particles are called Quarks.

Quark - any of a number of subatomic particles carrying a fractional electric charge, postulated as building blocks of the hadrons. Quarks have not been directly observed, but theoretical predictions based on their existence have been confirmed experimentally.

There are three Quarks in each Proton and Neutron. Quarks are held to each other by particles called Gluons.

Gluon - a subatomic particle of a class that is thought to bind quarks together.

Wrap your brain around these crazy facts:

It would take 136,000 atoms side-by-side before we could see them.

To get an idea of scale, if a hydrogen atom were roughly the size of a dime, the orbital electrons would be ½ mile away. The space between them is empty. Or if an atom were the size of a movie theater, the nucleus would be the size of a postage stamp and that stamp would hold 99.9% of the atom’s mass.

A typical human cell has roughly 100 trillion atoms.

A human hair is about 1 million carbon atoms wide.

A single drop of water contains about 2 sextillion atoms of oxygen (that’s 2,000,000,000,000,000,000,000) and twice as many hydrogen atoms.

The atoms that are in the water we drink are the same atoms that once made up the dinosaurs–and everything else that was once on this planet…or the universe as far as that goes.

The atoms we breathe are the same atoms that Galileo, Michelangelo, Jesus–everyone who has ever lived–once breathed.

The atoms that make us up as an individual will some day be parts of other existing things.

Now you’re a little smarter, Girlfriend — And so am I.