• Question: What are atoms?

    Asked by jimmyholt356 to Vince on 25 Jun 2013.
    • Photo: Vince Hall

      Vince Hall answered on 25 Jun 2013:


      Atoms make up molecules. They are tiny bundles of things called neutrons, protons and electrons.

      Neutrons are tiny particles that have no electrical charge, with a mass of about 10^-27 kg. That’s tiny indeed, one gram is 10^-3 kg, a milligram is 10^-6 kg. So a milligram is about 1, 000, 000, 000, 000, 000, 000, 000 times heavier than a neutron.
      Protons are about the same size and weight (mass) as neutrons, but they have +1 electrical charges each.
      electrons are about 1/1800 times the weight of protons, and have a charge of -1 each. That charge is about 1.6×10^-19 Coulombs. 1 Coulomb is the charge transported by a current of 1 Amp(ere) per second. So that’s a pretty tiny charge.

      Electrons are fundamental particles, but neutrons and protons are not.
      Electrons are part of a group leptons, which includes muons, tau particles, these are all charged.
      Then there are the neurinos, these are all un-charged (have no charge), and are really, really tiny. There are billions of neutrinos passing through the tip of your finger every second, and you’ll probably never notice any of them, they don’t react to much at all.

      Neutrons and protons are made of fundamental particles called up quarks and down quarks. It takes 2 down quarks and 1 up quark to make a neuron, plus some gluons to glue it all together. It’s thought that the Higg’s boson gives this stuff mass some how.
      A proton is similar, but it’s made of 1 down quark and 2 up quarks (other way around).
      This is called baryonic matter. There are other things that are made or stranger stuff.

      “String Theory” says that these quarks and electrons are made of tiny strings that vibrate to make different types of quarks, leptons and other fundamental particles. String Theory is not proven, but it is the best answer we have so far.

      Hope that wasn’t too heavy!

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