Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Nicholas on 18/01/2009 10:42:42
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Nicholas asked the Naked Scientists:
Hello, my name is nicholas and i'm 14 years old.
I was wondering if i have got the following right or wrong, or have missed anything out.
Atoms consist of charged Protons, Neutrons and Electrons, there form the atoms nucleus. Protons, Neutrons and Electrons are classed as Hadrons and Hadrons are put into two categories, Baryons and Meson. A Hadron is made up of Perks.
If i have forgot something or got something totally wrong, please tell me and if you could, correct me.
Many thanks
Nicholas
What do you think?
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Neutrons are not charged. Indeed, hadrons are composed of two classes of particle: mesons and baryons. Mesons include the lighter pion and kaon particles; baryons are the heavier particles that include protons, neutrons, atomic nuclei in general, and hyperons, very heavy particles that decay into protons or neutrons.
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The physicists will be able to tell you a lot more [:)] [:)]. Its a very good question though [:)]
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Nicholas - welcome to TNS.
Protons & neutrons form the nucleus of an atom. Protons carry positive charge and neutrons, as the name suggests, are neutral. The vast majority of the mass of the atom is contained within the nucleus.
Protons & neutrons are made of quarks (not perks). There are 6 types of quark but protons & neutrons comprise only 2 - the up quark & the down quark. Neutrons have 2 downs & 1 up, protons have 2 ups & 1 down. These quarks carry different charge. The up quark's charge is +2/3 and the down quark's is -1/3.
You can see that by adding these in the appropriate combinations you get +2/3 * 2 -1/3 = 1; a proton with charge 1 or -1/3 * 2 +2/3 = 0 which gives you a neutral neutron. Quarks are held together by the strong force.
Electrons form a "cloud" around the nucleus. It used to be thought that electrons orbited the nucleus in the same way that planets orbit the sun. However, the advent of quantum physics showed this not to be the case.
Electrons carry negative charge. It is the electromagnetic force that keeps electrons in their place.
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Atoms consist of charged Protons, Neutrons and Electrons, there form the atoms nucleus. Protons, Neutrons and Electrons are classed as Hadrons and Hadrons are put into two categories, Baryons and Meson. A Hadron is made up of Perks.
The answers you have received look good to me. One thing that was missed is that electrons are not hadrons. Electrons belong to the class of Leptons. You might think of it as hadrons are stuff inside the nucleus leptons are stuff outside.
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A strange fact emerges if you add up the masses of the quarks that constitute a Proton or Neutron.
taking the average quoted mass of the up quark as 5 Mev and the down at 10 Mev the total for a proton is 20 Mev whereas the mass of a proton is 1 Gev the balance being made up by the binding energy of the massless Gluons that hold it all together.
So it can be said that Atoms consist virtualy all of pure energy
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As Vern said, electrons are not hadrons. The word "hadron" comes from an ancient Greek word meaning "thick, heavy or fat". Protons & neutrons are extremely heavy compared to electrons (the proton has a mass 1836 times that of the electron).
"Lepton" comes from the Greek for "thin". This name was used because the first leptons discovered had low mass. However, since then others have been found that have much greater masses.
Here is a link to a description of the Standard Model of particle physics. It should tell you most of what you want to know.
http://www.benbest.com/science/standard.html (http://www.benbest.com/science/standard.html)
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Great link DoctorBeaver. It brings up a question I've never found a suitable answer for though. The Top Quark is one of the components of a proton, yet it by itself is much more massive than a proton. Is everyone comfortable with this?
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Vern
Please produce your evidence that the top quark is a constituent of Protons.
This is a very short lived particle only observed in collider experiments and has never been associated with every day matter.
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Vern - There are no top quarks in a proton, only 2 ups & 1 down. The UQ has a mass of 1.9 MeV and the DQ is 4.4 MeV.
As Syhprum stated, the TQ is a very short-lived particle (mass 178GeV) and thus far no-one has found a use for it.
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From the Standard Model link above.
Because the proton & neutron baryons are stable particles, it is not surprising that they are composed of the lightest & most stable quarks: the up-quarks and the down-quarks. A proton is composed of two up-quarks & one down-quark, whereas a neutron is two down-quarks & one up-quark. For a proton, for example, the masses of two up-quarks & one down-quark accounts for only about 2% of the mass and 30% of the spin -- showing the considerable contribution of gluons and raw (kinetic & potential) energy (E =mc2) to the total mass and spin of a proton.
Maybe I'm confusing Top quark with up and down quark. I don't have any evidence that the Top quark exists.
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Vern - There are no top quarks in a proton, only 2 ups & 1 down. The UQ has a mass of 1.9 MeV and the DQ is 4.4 MeV.
As Syhprum stated, the TQ is a very short-lived particle (mass 178GeV) and thus far no-one has found a use for it.
Thanks; I was confused about that.
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From the Standard Model link above.
Because the proton & neutron baryons are stable particles, it is not surprising that they are composed of the lightest & most stable quarks: the up-quarks and the down-quarks. A proton is composed of two up-quarks & one down-quark, whereas a neutron is two down-quarks & one up-quark. For a proton, for example, the masses of two up-quarks & one down-quark accounts for only about 2% of the mass and 30% of the spin -- showing the considerable contribution of gluons and raw (kinetic & potential) energy (E =mc2) to the total mass and spin of a proton.
Maybe I'm confusing Top quark with up and down quark.
I think you probably are.
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i Searched from google only..
An atom is the smallest particle into which an element can be divided without losing its chemical identity. Atoms consist of a heavy central nucleus surrounded by a cloud of negatively charged particles called electrons. The nucleus contains positive particles (protons) and electrically neutral particles (neutrons).
Here is an interesting structure and its inside elements app i found describes the structure and its inside elements. In addition it has a quiz at the end to make your learning exciting. here is the link ajax.insideatom
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Nicholas asked the Naked Scientists:
Hello, my name is nicholas and i'm 14 years old.
I was wondering if i have got the following right or wrong, or have missed anything out.
Atoms consist of charged Protons, Neutrons and Electrons, there form the atoms nucleus. Protons, Neutrons and Electrons are classed as Hadrons and Hadrons are put into two categories, Baryons and Meson. A Hadron is made up of Perks.
If i have forgot something or got something totally wrong, please tell me and if you could, correct me.
Many thanks
Nicholas
What do you think?
One thing of importance which was omitted so far is the fact that mesons are composed of two quarks, one of which is an antiquark.
Summary: Hadrons are made of quarks. The hadrons which consist of three quarks are called baryons, and he hadrons which consist of a quark-antiquark pare are called mesons. The antiquark in the meson is not necessarily the antiparticle of the mesons quark.
The term "cloud" was used here and is used in most textbooks on quantum mechanics and chemistry to refer to the region around the nucleus of an atom where electrons are found. The problem with that analogy is that it gives the wrong impression of what's going on. The electron cloud is merely a visual aid which shows the probability densities of where the electron may be found when its position is measured. It does not have a real physical existence as a real cloud which consists of particles of water. For example; a hydrogen atom has one electron but the electron cloud which represents it is shown to exist smeared out over region of space.
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Pete - what are mesons?
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In simple terms, an atom is the smallest possible amount of a chemical element, thus the atom of the element we call gold is the smallest piece of gold possible.
All atoms are made from the smaller tiny same bits, called subatomic particles , not the atom itself which is larger. Thus; if you divided up an atom of gold, and put the smaller bits into a pile, there would be something different left, smaller things that would no longer be gold, but a host of subatomic particles.
as indicated below.
Alan
https://en.wikipedia.org/wiki/Subatomic_particle
Six "flavors" of quarks: up, down, bottom, top, strange, and charm;
Six types of leptons: electron, electron neutrino, muon, muon neutrino, tau, tau neutrino;
Twelve gauge bosons (force carriers): the photon of electromagnetism, the three W and Z bosons of the weak force, and the eight gluons of the strong force;
The Higgs boson.
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Pete - what are mesons?
You know how a baryon, such as a proton or neutron, are particles made of three quarks? Well a meson is a particle that is made of one quark and one antiquark.
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Outside of the nucleus a neutron decays into a proton, electron, and neutrino
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In 1934 Yukawa proposed a theory of the strong force. Cosmic ray detections brought to light the pion and muon at around the same time. While the muon is a lepton the pion is the intermediate mass meson that Yukawa was looking for. Intermediate mass since its mass falls between that of the proton and electron. The mesons are integer spin bosons with the lighter ones transmitting the strong interactions binding together the nucleus. Heavier mesons are thought to have been created during the big bang but are now only created in high energy colliders.
https://en.m.wikipedia.org/wiki/Meson (https://en.m.wikipedia.org/wiki/Meson)
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As an aside, since the heavier mesons require high energy they may well play a part in the (speculative) combination of the forces of nature in objects such as black holes. During the big bang the decay of and the subsequent disappearance of the heavier mesons could have caused the subsequent separation of the forces.