User Tag List

Results 1 to 4 of 4

  1. #1
    Senior Member
    Join Date
    Nov 2009
    MBTI
    INFP
    Posts
    470

    Default Atomic disguise makes helium look like hydrogen

    http://www.newscientist.com/article/...-hydrogen.html

    "In a feat of modern-day alchemy, atom tinkerers have fooled hydrogen atoms into accepting a helium atom as one of their own. The camouflaged atom behaves chemically like hydrogen, but has four times the mass of normal hydrogen, allowing predictions for how atomic mass affects reaction rates to be put to the test.

    A helium atom consists of a nucleus containing two positively charged protons and two neutrons, encircled by two orbiting electrons which carry a negative charge. A hydrogen atom has just one proton and one electron. Donald Fleming of the University of British Columbia in Vancouver, Canada, and colleagues managed to disguise a helium atom as a hydrogen atom by replacing one of its orbiting electrons with a muon, which is far heavier than an electron.

    Because it is so heavy, the muon sits 200 times closer to the helium nucleus than the electron it replaces and cancels out one of the nucleus's positive charges. The remaining electron then behaves as if it were orbiting a nucleus with just one positive charge, just like the electron in a hydrogen atom. The difference is that the nucleus is 4.1 times heavier than normal.

    Fleming and his colleagues used this "super-heavy hydrogen", to test the effects of mass on chemical reaction rates. A lone hydrogen atom can form a new hydrogen molecule by stealing one of the two atoms from a pre-existing hydrogen molecule – but for that to happen there has to be enough energy available to break the bond holding the existing molecule together.

    Quantum tunnels

    According to quantum mechanics, it is not always necessary to climb over this energy barrier: instead, particles can "tunnel" through it. But the heavier the particles are, the harder it is to tunnel, so the less frequently the partner-swapping reaction takes place.

    Two hydrogen isotopes, containing one or two neutrons and with two or three times the mass of normal hydrogen, can be used to test this. An even heavier isotope, with three neutrons, exists but decays too quickly. Muonic helium, which has the same mass as this isotope, lasts long enough to react with a hydrogen molecule.

    Fleming's team shot muons produced at the TRIUMF accelerator in Vancouver into a cloud of helium, molecular hydrogen and ammonia. The helium atoms captured the muons, then pulled hydrogen atoms away from the molecular hydrogen and bonded with them.

    The team compared how long this took with the rate of the same reaction using normal hydrogen, and with a reaction rate recorded in 1987 when a type of ultra-light hydrogen, called muonium, was used. Chemists formed this by replacing the proton in a hydrogen atom with an antimuon, the muon's positively charged antimatter partner.

    'Very sexy'

    As expected, the reaction with the disguised helium was the slowest, followed by normal hydrogen, then the light hydrogen. The rates perfectly matched predictions from quantum mechanical calculations led by Fleming's teammate Donald Truhlar of the University of Minnesota in Minneapolis.

    The way any physical system changes with time can, in theory, be predicted from the quantum states of its particles. Most reactions involve far too many particles for this to be practical, but Truhlar says the hydrogen reaction was just simple enough.

    Millard Alexander of the University of Maryland in College Park calls it "very sexy nuclear chemistry"."

  2. #2
    resonance entropie's Avatar
    Join Date
    Apr 2008
    MBTI
    entp
    Enneagram
    783
    Posts
    16,761

    Default

    Good old Heisenberg would have tried to get an eye on that, nice . Fusion we are coming
    [URL]https://www.youtube.com/watch?v=tEBvftJUwDw&t=0s[/URL]

  3. #3
    The Eighth Colour Octarine's Avatar
    Join Date
    Oct 2007
    MBTI
    Aeon
    Enneagram
    10w so
    Socionics
    LOL
    Posts
    1,366

    Default

    The method actually looks like a clever, but straightforward test. The tricky bit is actually isolating the exotic atoms. http://en.wikipedia.org/wiki/Exotic_atom

  4. #4
    Senior Member Thisica's Avatar
    Join Date
    Feb 2011
    MBTI
    NiTe
    Enneagram
    5w4
    Posts
    384

    Default

    I've seen a video on this news item as well, by Professor Poliakoff...from the Periodic Table of Videos!
    “To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty, & leave the rest for others that come after you, than to explain all things by conjecture without making sure of any thing.”—Statement from unpublished notes for the Preface to the Opticks (1704) by Newton.

    What do you think about me? And for the darker side, here.

Similar Threads

  1. 8 Cognitive Processes Dominant and 2ndary Interactions: What They Look Like
    By Usehername in forum Myers-Briggs and Jungian Cognitive Functions
    Replies: 2
    Last Post: 06-26-2012, 12:23 PM
  2. Who do you look like?
    By Ivy in forum The Fluff Zone
    Replies: 246
    Last Post: 03-10-2008, 06:20 AM
  3. How does auxiliary function look like?
    By alcea rosea in forum Myers-Briggs and Jungian Cognitive Functions
    Replies: 4
    Last Post: 02-28-2008, 11:18 PM
  4. [Ni] Ni - What does it look like in real ife?
    By INTJMom in forum The NF Idyllic (ENFP, INFP, ENFJ, INFJ)
    Replies: 65
    Last Post: 10-12-2007, 05:25 PM
  5. Looks like The_Liquid_Laser might be a daddy!
    By ladypinkington in forum The Bonfire
    Replies: 48
    Last Post: 10-05-2007, 03:31 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Single Sign On provided by vBSSO