A look at some of the chemical compounds that can be used to colour paint. Not all of these are still in use - for example, cadmium & chromium compounds are toxic, so their use is now rare. You can read more about the cause of the colours here: http://wp.me/p4aPLT-8N
Thanks to ve-ve-whats-cooler-than-cool for the question that inspired this graphic!
Particles and Matter
According to the Standard Model, ordinary matter is made of fermions, or rather, by the first-generation fermion particles, namely, electrons and up and down quarks, which make up protons and neutrons in various combinations (approximately, a proton is made by the combination u-u-d, while a neutron by the combination u-d-d). The particles of the second and third generations have a larger mass, so they are highly unstable and can only be produced in the laboratory.
I’m not quite clear on the last part of the ask. Quarks are indeed researched through smashing, but their existence was first hypothesized theoretically by Murray Gell-Mann and George Zweig in 1964. Then the hypothesis was confirmed at the end of the sixties from studies conducted at the Stanford Linear Accelerator Center (SLAC ). When high energy electrons were fired at protons and neutrons —analyzing the energy and angular distribution of electrons— they observed that some of these electrons were bumping into electrically charged, point-like objects contained inside protons and neutrons, proving in this way quarks’ existence.
So, the atom is not the smallest particle, but the use of subatomic particles makes sense only in nuclear physics. The other physical and chemical processes make sense at the atomic level and, in fact, the atom is now defined as the smallest unit of an element that retains all the element’s properties.
Best of 2013!
- Physicists: Earth May be Breaking Through Dark Matter Walls
- Black Holes May Turboboost Super-Civilizations
- Giant, Magnetized Outflows From Our Galactic Center
- Nearby Ancient Star is Almost as Old as the Universe
- Higgs Boson = Cosmic Doomsday?
- Why Are Black Holes so Bright?
- 'Monster' Starburst Galaxies Discovered in Early Universe
- Curtains Down for the Black Hole Firewall Paradox: Making Gravity Safe for Einstein Again
- Planck Shows Almost Perfect Cosmos—Plus Axis of Evil
- Einstein’s Gravity Theory Passes Toughest Test Yet
- Strange New Bursts of Gamma Rays Point to a New Way to Destroy a Star
- Are the Newly Discovered Planets Ideal SETI Targets?
- Giants Elliptical Galaxy Harbors Largest Known Black Hole in Universe
- Hunting for Alien Megastructures
- "Laws of Physics for a Holographic Universe"—New Theories of Space-Time
- Giant Black Hole’s Dust Oddity Surprises Scientists
- Time to Plan for A Mission to Alpha Centauri
- Obese Black Hole Galaxies Could Reveal Quasar Secrets
- If This Theory is Correct, We May Live in a Web of Alternate Timelines
- Our Lopsided Universe is Darker, Lighter, Slower, Older & More Mysterious Than We Thought
- How Giant Black Holes Spin: A New Twist Revealed
- Oceanic Black Holes Found in Southern Atlantic
- 'Listening' to Black Holes Form With Gravity Waves
- Inside the Enigma of Black Holes
- Astronomers Discover Densest Galaxy Ever
- Did a Hyper Black-Hole Spawn the Universe?
- Supermassive Black Holes at Galaxy Centers—“Exit Doors From Our Universe”
- "Other Universes Are Pulling on Our Universe"—New Planck Data Triggers Controversy
- Seven-Planet Solar System Found
- How Did Supermassive Black Holes Grow So Big?
- Black Holes Don’t Make a Big Splash
- "Distant, Younger Galaxies Look Very Different Than Nearby Galaxies"
- New Type of Black Hole Quasar Discovered
Each of these tubes is filled with a pure elemental gas* before being excited with 20,000 V. This causes the electrons in the atoms to jump to higher energy states which then emit light when they relax back down.
The light emissions have been diffracted here to show the individual wavelength components, each of which represent the jumps electrons in a particular element can make.
This is an important tool in identification and is used in techniques like ICP (Inductively Coupled Plasma), and FAA (Flame Atomic Absorption) where samples are vaporized/excited under controlled conditions to measure the light they emit.
This equipment is so sensitive it can detect down to the parts per trillion (1 gram /1 million tonnes) and billion range respectively when coupled with a mass spectrometer.
*Except the air which is mainly nitrogen and oxygen.