Why is Helium part of the noble gases according to the octet rule?
817099
Because the las energy lawyer is complete. The octet rule says that the last energy lawyer must be complete or have 8 electrons to be inreactive.
259405
Total volume =( 1 + 2 ) dm3 = 3 dm3.\nUse Boyles  pV = constant on both gasses.\nThe partial pressure of helium is 2/3 kPa.\nThe partial pressure of neon is also 2/3 kPa.\nDalton's law:\nthe pressure of the mix is 2/3 kPa + 2/3 kPa = 1.3 kPa.
762651
2+, because to reach the noble gas configurationof a full outermost shell, 2 outer electrons have to be lost.
112298
Ideal gas laws assume that all particles are spherically symmtric and engage only in elastic collisions.  They ignore all other types of molecular energy (rotation in other planes of symmetry or asymmetry, bond stretching/compressing/bending, rotation about a molecular bond--all these things can and do absord energy from a collision), and they negate the effects of all intermolecular forces, like dipole interations, hydrogen bonding, London dispersion forces, etc.\n\nIn gases like helium, the atoms are basically spherically symmetric, and most of these random forces are neglible.  Hence, ideal gas laws work really well for these--only at really ridiculously low temperatures and high pressures do these forces manage to liquify helium.  The larger you molecule is--and I'm not talking about mass so much as the number of chemical bonds--the less ideally it behaves.  The greater the heterogeneity of a gass, the less ideally it behaves.  The greater the polarity (eg seperation of charges) displayed by the molecule, the less ideally it behaves.
773257
Re:  For Helium, the "2" is called the atomic number and it means that Helium has 2, protons, 2 nuetrons and 2 electrons.\n\nFor Lawrencium (Lr) it should show 103 as its atomic number.  That means that Lr has 103 protons, 103 neutrons and 103 electrons.  \n\nThe 2, 8, 18, 32, 32, 8, 3 numbers are showing electrons per shell (different subject) but you'll see that if you added all the numbers 2+ 8+ 18+ 32+ 32+ 8+ 3 = 103.  103 is the total number of electrons Lr has.   \n\n____________________________________________\n\n\n\n\nFor a Normal Neutral Atom, the number of protons (p+), neutrons (n) and electrons (e-) are all the same. \n\nJust look up the atomic number from the periodic table to determine them.\n\nFor example:\n\nC: 6p, 6n, and 6e-.\nN: 7p, 7n, and 7e-.\nK: 19p, 19n, and 19e-.\n\nNow, Determine the number of p, n, and e- for Ca.\n\n\n\n\n\n\nIf you guessed, 20p, 20n, and 20e-, you are Correct!\n\n\nNote that, if you add the number of the atom's p and n you will get the Mass number (Z). \n\nThe periodic table shows Z of calcium as 40.078 because 20p + 20n = 40 (amu) \n\nAnother Example: Oxygen, having atomic number of 8, will have:\n8p, 8n, and 8e-. This means that Oxygen will have the mass number of 16 because; p + n = Mass number (Z).\n\n______________________________...\n\nFor Isotopes:\nIsotopes are atoms that have same number of protons but different number of neutrons.\n\nYou've already seen that normal Carbon has: 6p, 6n, and 6e-.\n\nThis normal carbon is called "Carbon-12". The "12" denotes its Mass number (Z). Which is p + n.\n\nThere are isotopes of Carbons and one of them are Carbon-13. Since you already know that Carbon must have 6p, Carbon-13 has 7n. 13 - 6 = 7. The number of the electrons are still the same as number of proton. \n\nIn another words, simply subtract the number of protons from mass number to determine the number of neutrons.\n\nNow, determine the number of p, n and e- of Fluorine-19:\n\n\n\n\n\nIf you guessed 9p, 10n, and 9e-, you are Correct!\n\n______________________________...\n\nFinally, there are ions. Ions means that an atom has either gained or lost electrons. Keep in mind that eletrons are NEGATIVE in nature (e-) and when an atom Gains e-, it becomes More negative.\n\nFor example: Fluoride ion, F- means that it has GAINED one electron compared to its neutral F state. Therefore;\n\nF has 9p, 9n, and 9e-, But F- has 9p, 9n, and TEN e-.\n\nO has 8p, 8n, and 8e-, But O2- has 8p, 8n and TEN e-, because O2- means that it has Gained 2 more electrons than its normal O state. \n\nNow, determine the p, n and e- for P3-.\n\n\n\n\n\nIf you guessed 15p, 15n, and 18e- you are Correct!\n\nFor atoms that have positive charges (cation), remember that they LOSE e- to become positive. So, Li+ has 3p, 3n and 2e-. \n______________________________...\n\nKeep in mind that you need to know how to combine all three of the ideas mentioned above. For example, you may be requested to determine the p, n and e- of Magnesium-25 ion. \nYou need to know that since Magnesium is in Group IIA, it will turn into 2+ ion. Therefore Magnesium-25 ion will have 12p, 13n, and 10e-. \n\nI hope this answers your question. Good luck!
476212
Atoms want to be like a "noble gas" with a filled outer shell.  I think it has to do with being in a stable state.  For Mg, it's a lot easier to drop 2 electons to look like Ne rather than gain 6 to look like Argon.\n\nThis very basic premise only works for things on the "sides" of the table.  The transition elements in the middle are a bit different.
888387
Noble gases are also called inert gases because they do not react chemically.  There the one in the last column of the table.  Their last electron layer is full (all 8 electrons --2 for helium-- are there) and that's why they don't (usually) form bonds.
844206
The answer is simple. All elements (whose basic units are atoms) except the noble gases, have less than 8 electrons in their valence shells.  The rule that states that atoms should have 8 electrons to achieve stability is called The Octet Rule.\n\nhttp://en.wikipedia.org/wiki/Octet_rule\n\nThe way that they can attain 8 electrons is by forming BONDS: by either sharing electrons (covalent bond) or by gaining/losing electrons (ionic bond).   This is the main reason why atoms react: to attain 8 valence electrons.\n\nIf we look at it at another angle, we can say that atoms react in order to decrease energy.  This comes from the principle that bond formation results in loss of energy, and that stability comes from decreased energy.\n\nHope that helps.
537794
Okay, to begin with; the molecular orbital theory is based on the "octet rule."  This means that, with exceptions of hydrogen and helium of course, an atom is most stable with 8 electrons (the octet) in its outer shell.  \n\nA diatomic molecule is a pair of identical atoms forming a small molecule.  The most common diatomic molecules are in the halogens; Cl, F, I, Br.  These atoms each lack one electron from a full octet, and will covalently bond in pairs to each gain a full octet.  Oxygen gas (O2) will bond in a double pair, sharing four electrons to gain an octet on each atom.  \n\nBeryllium contains 4 electrons in total.  The electronic configuration is 2:2 or if you use the other method is 1s2 2s2.  A full octet would be 2:8 or 2:0 to gain the most stability, and the Be2+ is actually in use in labs (2:0).  \n\nBecause it would need to gain electrons from or donate them to some other element with a greater number or greater need, beryllium can't form a diatomic molecule or a pair with another of itself.  \n\nIt is difficult to explain without pictures, but there are a few shell pictures available at Chemical Elements which will let you compare these elements.
271262
Well, the elements in column 1 when ionized have a +1 charge. The elements in column 2 have a +2 charge when ionized. The elements in column 7 when ionized have a -1 charge, and the column 6 elements form -2 charged ions.\n\nThe column 8 elements are called noble gases, because they have a full valence shell of electrons and don't bond readily with anything. They don't normally ionize.
762215
Noble Gases:  He, Ar, Ne, Xe\nHalogens:  F2, Cl2, Br2, I2, At2\nOthers:  N2, O2
483657
There is very little helium on earth as nearly all present during and immediately after the earth's formation has long since been lost as it is so light. Just about all the helium remaining on the planet is the result of radioactive decay. While there is some helium in the atmosphere, currently its isolation from that source by liquefaction and separation of air is not normally economic. This is bacause it is easier, and cheaper, to isolate the gas from certain natural gases. Concentrations of helium in natural gas in the USA are as high as 7% and other good sources include natural gas from some sources in Poland. It is isolable from these gases by liquefaction and separation of from the natural gas. This would not normally be carried out in the laboratory and helium is available commercially in cylinders under pressure.
703814
211_____207_____4\n      Bi  -->__Tl +____a    (a helium nucleus) \n83_______81_____2
269322
1. All the members of the noble gases have a full shell of valence electrons, so they don't easily bond with other atoms.\n\n2. Because of the full shell, the noble gases have very weak intermolecular forces (IMF's), so they all have very low melting and boiling points. Helium actually doesn't become a liquid at normal atmospheric pressure until you get down to 4.22 K (-452 degrees Fahrenheit).\n\n3. They don't. Well, not usually. The larger noble gases (Krypton and Xenon) will bond with others, but only when using an expanded octet, in the d orbital. This makes compounds such as xenon tetrafluoride, XeF4. However, Helium and Neon will not react with anything, as their ionization energy is extremely high and their electron affinity is very low.\n\nNOTE: The answers above me are WRONG. Noble gases definitely do not form diatomic compounds. They are confusing the noble gases with the halogens, the elements that are in the second to the right column on the periodic table. It took all the way until 1962 for a chemist to synthesize a true noble gas compound, Xe[PtF6]- (xenon hexafluoroplatinate).\n\nEDIT: Tarangoyal, I'm reporting you for plagiarism. That answer is virtually identical to the first answer. There's no way that's a coincidence. You even made the same mistakes.
791559
Let's see, this may be a bit difficult to explain, but since no one else has so far, I figured I'd give it a shot.\n\nI don't have a periodic table in front of me, so I'll do my best to explain.  There is a double bond between N and one of the O's because of something called "in-bonds."  You determine the number of "in-bonds," or bonds in between elements by subtracting the number of valence electrons that you have all together from the number that you need for everything to be stable.  In this case, forget about H for the time being, and you have N03.  Each element needs 8 electrons to fill its valence shell right?  Multiply 8 by 4, since there are 4 elements, and you get 32.  However, you only have 24 electrons to go 'round.  The difference is 8, there for you can have a total of 8 electrons, or 4 individual bonds in between the elements.  It doesn't matter which O gets to share the double bond with N, as they are all the same.\n\nThe double bond was used in HNO3 and not NF3 because I believe you had enough electrons to go around, therefore there were no "in-bonds."\n\nI hope this helps to clear up your questions.
905246
Yes.  You just begin to take electrons away from the outermost, least stable orbitals.  In this case the first two electrons will come from the 4s2 shell, and then the one from the 3d.  This will leave you with just [Ar], which is a noble gas, and if you remember back to the beginning of chemistry, elements become ionic (gain or lose electrons) because they all wish to achieve this noble gas configuration.
641799
It depends on the octet rule. If the element fulfills its octet, or has 8 valence electrons(such as the noble gases) then it will be very stable. The farther they are from fulfilling the octet rule, the less stable the element is.