why  is a test tube full of bare neutrons heavier than the earth?
594590
The word "heavier" implies the weight of the object....a force.  Weight is the force acting on a mass due to gravity.\n\nEither you have changed the wording of the statement so much so that it has changed the meaning or that is one poorly written "phisiks buk" [physics book].  If you are indeed quoting out of the book, throw that peice of trash out the window now.\n\nWhat you are probably refering to is the Earth's density versus the density of a neutron.\n\nThe density of a Neutron star (which is made up of only neutrons) is about 3 E14 g/cm^3.\nThe Earth has an average density of about 5520 kg/m^3, or about 5.52 g/cm^3.  You can see the drastic difference in densities.\n\nIf you said you had a "test tube full of bare neutrons" and that test tube has a volume of...50 mL, it would have a mass of 1.5 E13 kg.  The Earth has a mass of about 5.97 E24 kg.  Clearly the Earth is more massive, and thus under the same gravitational field, "heavier".
642453
proton and neutron, the electrons are on the outer shell
813411
Well, you couldn't, because my calculations tell me that if you get closer than about 5000 km. from a neutron star, the tidal forces, that is the difference between the gravity pull on your feet and your head, would stretch you out and kill you.  If you built a strong robotic vehicle that could get to within 1600 km of the surface, the rock would be pulled to powder by tidal forces before it hit the surface.  The bits would hit the surface at up to a third of the speed of light, 100 000 km/second, depending on the mass of the neutron star.  They'd get so hot on impact that they'd emit X-rays, which, as they climbed against the neutron star's gravity, would lose energy, and you'd see them from a safe distance as soft X-rays, UV and visible light.The amount of energy radiated would be about 10^15 joules; comparable to the Hiroshima bomb.  The mass of the neutron star would increase by about half a kilogramme or so.  The crust of a neutron star probably consists of iron or diamond, and your rock would end up as one of these.  It would be interesting to perform this experiment, from a safe distance, with a robot probe, on a neutron star within a whisker of collapsing into a black hole, to see what gives.
73226
Protons is the atom's atomic number.  It gives the atom its certain "chemical properties".  The proton has a weight of 1.  The neutron is a combination of a proton and electron roughly as evidenced by storing a neutron for more then 15 min and it will turn into a hydrogen atom.  For all intensive purposes the electron has no weight.  The neutron weighs 1 as well. When you combine the numbers of protons and neutrons in an atom you get the weight.  The neutrons act as glue for the atom and help keep it together.  Thus Uranium 235 is more unstable then Uranium 238. (235 is what they use in reactors).  The electron is attracted to the proton. Electron(-) proton (+).  But as you get towards the left section of the table you have atoms that want to lose their electrons since the want full orbitals.  As you get toward the right side of the table you get atoms that want to gain electrons to fill their shells.  These atoms that have a positive charge are known as cations longer word = positive. Shorter word or Ion = negative.
726623
Electron Proton neutrons
668060
First of all: God doesn't exist so that explanation is out.\n\nHydrogen was not the only element that existed right after the big bang.  The universe was 75% Hydrogen and 25% Helium with trace amounts of what astrophysicists call 'metals' (which in astrophysics means anything other than Hydrogen or Helium and so rather confusingly includes such things as Oxygen and Nitrogen).\n\nThe rest were created by nuclear fusion reactions inside stars until Iron because a net energy gain is possible when fusing anything lighter than Iron.  Those heavier than Iron were created in supernova when the energy of the Iron core of a really massive star collasping into a Neutron Star allowed for Iron to be fused and some of the heavier stuff (includings things even heavier than Uranium) were expelled and ended up becoming part of our planet.\n\nThat is why there are 90 naturally occuring elements on Earth (not 92, there are two elements lighter than Uranium which don't occur naturally on Earth).
834645
Hm.  Okay.  Here's some stuff about atoms to get you started:\n\nJust like all things are made of atoms, all atoms for the most part are made up of the same three parts.  Protons, neutrons, and electrons.\n\nProtons and neutrons are comparatively really heavy.  Pretty much all the weight of an atom comes from these guys.  Because they're heavy, they don't move around a lot unless the whole atom is moving.  Instead they stick together in the center of the atom (also called the nucleus).\n\nElectrons live very different lives.  Unlike protons and neutrons, they are not only light but comparatively large.  They buzz around the nucleus like planets around a star... or perhaps more like beach balls around a sack of marbles.  A lot of chemistry has to do with electrons zipping around, being attracted to one thing or another... or more likely to several things at once.\n\nAnother important thing to know about the parts of atoms is their charge.  The charge in these parts come from the electric force, which (if you can imagine it) is a billion billion billion billion billion billion times stronger than gravity (yes, that's a one followed by 36 zeroes).  The electric force is also involved with electricity that we use in our houses and the like.\n\nThe pro- in proton comes from its positive charge.  To make things easy for themselves scientists just decided to say a proton has a +1 charge.  The neu- in neutron comes from it being neutral.  It has zero charge.  Electrons have the opposite charge of protons, so they have a -1 charge.  Pretty straightforward.\n\nAnd here's where things get interesting.  The name we give an atom (like helium or uranium or whatever) depends ONLY on the number of protons it has.  So, for example, an atom with two protons is helium, no matter WHAT else its got.  Neutrons hang out in the nucleus with protons, where they add to the weight of an atom but don't do much else.  And the REASON all those electrons are buzzing around a boring nucleus instead of being off somewhere else is because all those negative charges like to be near all those positive charges.  And since the electric force is so incredibly strong, you can bet that just about everything you run into is going to have as close to a zero total charge as it can get.\n\nSo there you have it.  Atoms in a nutshell.  Hope that helps!
985750
All elements with atomic number higher than 92 (Uranium) are artificially produced. To do so, they accelerate a neutron (which is hard since neutron has no charge) and then bombard a lighter nucleus with them. The nucleus absorbs a neutron, releases an electron (beta ray) and keeps a proton, so the atomic number will raise one number. (n -> e + p)\nThey do it again and again until they reach the element that they want. but the higher the atomic number, the lower the half life will be (they will last from few months to few micro seconds) when they say that an element is not yet produced but they put it in the periodic table, this means they have evidence that is should exist, but since the half life is short they are unable to detect it, so they have to wait for technology to advance so they can detect it.
474775
You would expect the sum of the rest masses of the quarks to be less than the mass of the proton or neutron.  A proton/neutron is a bound state of quarks made up of quarks and gluons.  With the gluons in there, you get more mass.  It has also been shown that the mass of a nucleus is greater than the mass of its constituent protons and neutrons.  This is because the "binding energy"  that is, the energy it takes to stick the nucleus together also adds to the mass of the nucleus.  \n\nSo, the quarks+gluons+binding energy=mass of proton/neutron\nYou can't really find out a velocity from that...
547549
From elementary chemistry it is known that the atomic structure of any element is made up of a positively charged nucleus surrounded by electrons revolving around it. An element’s atomic number indicates the number of positively charged protons in the nucleus. The atomic weight of an atom indicates how many protons and neutrons in the nucleus. To determine the number of neutrons in an atom, the atomic number is simply subtracted from the atomic weight.\n\nAtoms like to have a balanced electrical charge. Therefore, they usually have negatively charged electrons surrounding the nucleus in numbers equal to the number of protons. It is also known that electrons are present with different energies and it is convenient to consider these electrons surrounding the nucleus in energy “shells.” For example, magnesium, with an atomic number of 12, has two electrons in the inner shell, eight in the second shell and two in the outer shell.\n\nAll chemical bonds involve electrons. Atoms will stay close together if they have a shared interest in one or more electrons. Atoms are at their most stable when they have no partially-filled electron shells. If an atom has only a few electrons in a shell, it will tend to lose them to empty the shell. These elements are metals. When metal atoms bond, a metallic bond occurs. When an atom has a nearly full electron shell, it will try to find electrons from another atom so that it can fill its outer shell. These elements are usually described as nonmetals. The bond between two nonmetal atoms is usually a covalent bond. Where metal and nonmetal atom come together an ionic bond occurs.\n\nhttp://www.tech.farmingdale.edu/depts/met/met205/atomicbonds.html\n\nhttp://web.jjay.cuny.edu/~acarpi/NSC/5-bonds.htm
701573
a radioactive element is unstable because it has too many neutrons in its nucleus.
640285
The earth's weight is always changing, when a 200lb person is cremated they become 4lb of ash. Other factors are destruction like forest fires. astronauts go into space fuel gets consumed to get there, they bring food and other supplies that get used up there. I could go on forever, best person to talk to would be a physics teacher
1036071
If you could get one down there, it would likely melt before detonation. If you could solve that problem, then the result MIGHT depend on the yield of the weapon... but it would have to be a few million times stronger than today's strongest weapons, since the immense molten iron core of the earth handles pressures and forces far in excess of anything we will ever experience, and probably stronger than anything we could ever create in the next five thousand years. Nukes are only scary for fragile surface creatures in a relatively tiny area, not for fiery iron spheres that are the size of the moon.
425150
It is true that the neutron is heavier.  I can not remeber the exact numbers but it is not much heavier.  \n\nA neutron is basicly when you take a proton and an electron and combine them in to one particle (try this at home) thus the electric charges cancel out and it is a little bit heavier.  For the true mass you would have to include relitivistic effects.  \n\nbecause a proton is much heavier than an electron it is commonly stated that a proton has a mass of one, and an electron 0 and a neutron 1 as well.  And that is all well and good in most cases
867714
Indeed, it looks as if everyone is correct. You do round to the nearest whole number. \n\nThis gives you the most commonly occurring isotope for that element. In this case O-16, which gives you the total number of neutrons + protons. To get Neutrons subtract the Atomic No. from the AMU.\n\nOxygen has other isotopes (same element with different numbers of neutrons), thus different weights. Ex: O-15, O-14, O-17, etc.\n\nGet an "A".
1071240
I'm not exactly sure what your talking about, but if you go to unitednuclear.com I'm sure they will have the magnesium you're looking for, unless your talking about an actual test tube made out of magnesium which I've never heard of.
78209
Nope, the magnetic information (not electronic!) doesn't weigh anything, it's all related to the orientation of the "magnetic moment" (up or down) of the atoms i.e. the way atoms are turning (to make it simple). they're not heavier if they turn in one sense than if they does in the other