albertlee Posted October 29, 2004 Posted October 29, 2004 How many shells does a hydrogen atom have? I thought it only has 1 shell, because according to the periodic table, the row number indicates the number of shell (orbit) as Hydrogen is placed in the first row. Secondly, if it has only 1 shell, does that mean hydrogen can never loose 1 electron in its only shell? because otherwise it obtains no electron at all in its shell during ionic bonding. Any help?
Gilded Posted October 29, 2004 Posted October 29, 2004 A naked hydrogen, or H+, is a proton. Yes, a hydrogen atom can lose its electron for example, in the case of H2SO4, when it becomes HSO4- and H+.
swansont Posted October 29, 2004 Posted October 29, 2004 There are an infinite number of energy levels. But only one would be occupied at any given time, by a neutral atom.
albertlee Posted October 29, 2004 Author Posted October 29, 2004 So if Hydrogen can loose electron, this confuses me.... because, why H2O does not form in ionic, instead covalent, since it will be more stable? as oxygen atom need to take up 2 more electrons, as 2 hydrogen atoms can provide so... Albert
serunato Posted October 29, 2004 Posted October 29, 2004 because, why H2O does not form in ionic, instead covalent, since it will be more stable? as oxygen atom need to take up 2 more electrons, as 2 hydrogen atoms can provide so... Albert O- is not stable, OH- is a very strong bronsted base, meaning it will accept a proton. Kw=1e-14, meaning that there are 1e-14M H3O+ and OH- floating around in pure water. So it does ionize but the OH- is such a good base it picks it right up, and the H3O+ is such a good acid it gives it right up. This is evidenced by dueterated water mixed with water. In a matter of microseconds there is no D2O left it has all become DHO. The rate at which the hydrogens exchange if fast.
Primarygun Posted October 30, 2004 Posted October 30, 2004 because, why H2O does not form in ionic, instead covalent Stability is determined by the bond, shape , region of charge of molecules or formula unit. Covalent bond is very similar to ionic bonding, you may recongnise that in a water molecule, the oxygen molecules and one hydrogen atom share one pair. However, that pair is more close to the oxygen atom. In potassium oxide, the outermost shell electron of potassium is attracted by the oxygen atom. IT is not share. Hence, the nature of bond( covalent or ionic ) is determined of the attraction of the difference of two atoms,i.e. electronegativity.Personally, I enjoy the defintion of difference greater than 1.7 involve an ionic bond Fluorine has 4.0 which is the highest, second is oxygen 3.5 , while metals usually have that lower than 2.0.
albertlee Posted October 30, 2004 Author Posted October 30, 2004 Stability is determined by the bond' date=' shape , region of charge of molecules or formula unit.Covalent bond is very similar to ionic bonding, you may recongnise that in a water molecule, the oxygen molecules and one hydrogen atom share one pair. [/quote'] How come covalent is similar to ionic? covalent is sharing the electron, and ionic is either loosing or gainning the electrons.... I see no similarity for this.. However' date=' that pair is more close to the oxygen atom. [/quote'] What do you mean by "more close"? In potassium oxide' date=' the outermost shell electron of potassium is attracted by the oxygen atom. IT is not share.[/quote'] Can you tell what factor makes this bonding here opposing to the bonding of H2O? Hence' date=' the nature of bond( covalent or ionic ) is determined of the attraction of the difference of two atoms,i.e. electronegativity.Personally, I enjoy the defintion of difference greater than 1.7 involve an ionic bond Fluorine has 4.0 which is the highest, second is oxygen 3.5 , while metals usually have that lower than 2.0. [/quote'] How can you measure the electronegativity? Apreciate for furthur responds... I am just a chem beginner, sorry for not understanding this... Albert
Primarygun Posted October 30, 2004 Posted October 30, 2004 How come covalent is similar to ionic? covalent is sharing the electron, and ionic is either loosing or gainning the electrons.... I see no similarity for this.. They are bonded due to a force. This force is a electrostatic force which is attraction between oppositely charged ,i.e. particles electrons and proton(nucleus). What do you mean by "more close"? Carbon dioxide is a non-polar molecule while water molecule is a polar molecule. That means the "distances" of the pair between one atom and the other one are not equivalent at a particular time. [ Actually, electron is always not equivalent since they have different position which is contradict the fixed shell position, but the chance of pair in a polar molecule staying closer to higher attractive atom is higher. Can you tell what factor makes this bonding here opposing to the bonding of H2O? The attractive forces of the outermost shell electron and potassium nucleus are too small, in contrast to the strong attractive forces from the oxygen nucleus. Potassium atom then lose its outermost electron. Metal tends to lose electron to obtain stable octet(state). How can you measure the electronegativity? Electronegativity----a measure of tendency of the attractive forces from the nucleus of an atom. There are lots of stuff from the internet where you can get. Regarding to my little knowledge in chemistry, I have no idea. There are lots of professionals in this site who can help you. I enjoyed giving my time on helping you.
albertlee Posted October 30, 2004 Author Posted October 30, 2004 The only thing I dont get is: How do you know which molecule is polar and what is its negativity? By the way, PrimaryGun, you said that the more difference on negativity of two atoms, the more chance of ionic bonding it becomes.... but, is the range of negativity between hydrogen and oxygen very small? how can you know that? Albert
Gilded Posted October 30, 2004 Posted October 30, 2004 "is the range of negativity between hydrogen and oxygen very small? how can you know that?" OH (a polar covalent bond) is a bond of moderate electronegativity difference (1.4 actually). And if you want to know which atom the electrons are closest to, they're closer to the one with higher electronegativity. And about the "how can you know if it's small", perhaps you could think "when you spray oxygen with hydrogen, it doesn't form water. But when you heat the solution a bit, it does". For example, fluorine is a bitch because it has a big electronegativity difference with just about everything that's solid, making it hard to store. And because of the high difference, it doesn't even need to be heated to form bonds with... stuff. http://chemistry.allinfoabout.com/features/electronegativity.html <- electronegativities of some elements + some info about electronegativity
albertlee Posted October 30, 2004 Author Posted October 30, 2004 Glided, You mean H2O instead of OH, right? because OH is not a molecule, it's an ion... Secondly, according to the table, which one has a stronger electronegativity, NH3 vs H2O?? thx, Glided Apreciate for furthur responds
Gilded Posted October 30, 2004 Posted October 30, 2004 "Glided, You mean H2O instead of OH, right? because OH is not a molecule, it's an ion..." Yeah well, the oxygen does that bonding with two hydrogen atoms instead of just one when they react (who wouldn't like a threesome? WHOOPEE! Damn, I need sleep again.)
albertlee Posted October 30, 2004 Author Posted October 30, 2004 OK..... any way, again... according to the table Glided provided, which one has a stronger electronegativity, NH3 vs H2O??
Gilded Posted October 30, 2004 Posted October 30, 2004 Stop calling me Glided! :> There's Glider and Gilded here, so it's no wonder people are so confused. And as for your question, from what I've understood only molecules of covalent bonding have an overall electronegativity, so answering the question would be rather silly (or unpractical anyway).
albertlee Posted October 30, 2004 Author Posted October 30, 2004 Well, any other can answer my question of my previous post????
Primarygun Posted October 31, 2004 Posted October 31, 2004 How do you know which molecule is polar and what is its negativity? Study the geometry of molecules, study the shape. Have a look on it. electronegativity is the measure of atom only. It is proportionaly to Ionization energy. In other words, it is indeed a measure of atom. NH3 and H2O, every part of the molecule have different attraction to charged particles. Maybe the attractive forces of the strongest attractive part of H2O is stronger than that of NH3 since that part of H2O has a lone pair + an oxygen atom (3.5) But NH3 only has a lone pair + a nitrogen atom(3.0)
albertlee Posted October 31, 2004 Author Posted October 31, 2004 PrimaryGun, are u Chinese???? because I find ur logic of conversation in English a bit different to others here.... ANy way, Study the geometry of molecules' date=' study the shape.Have a look on it.[/quote'] So this tells whether the molecule is polar... but what geometry, shape tells it is polar? secondly, for more reasoning, why this shape tells it is polar? I have checked in my textbook, the lone pairs repel the polar bonds, giving the molecule its shape.... for eg, NH3, the lone pairs at the top of N, repel against three polar bonds connecting to H, and while those three are repeling too, so they move to the bottom.....forming a pyramid..... Any more information will be apreciated electronegativity is the measure of atom only. It is proportionaly to Ionization energy. In other words' date=' it is indeed a measure of atom.[/quote'] A measure of negativity of atom, right? NH3 and H2O' date=' every part of the molecule have different attraction to charged particles. [/quote'] Umm.... Chemistry is indeed quite complex, but interesting... I always seek to know more, but there is always too much for me to know.... Maybe the attractive forces of the strongest attractive part of H2O is stronger than that of NH3 since that part of H2O has a lone pair + an oxygen atom (3.5) But NH3 only has a lone pair + a nitrogen atom(3.0) I dont really get the meaning for this,.. and I think you made a mistake on either NH3, or H2O, because why use "only" for NH3, while both have the same amount of lone pairs? Thx in advance!! Albert
Gilded Posted October 31, 2004 Posted October 31, 2004 "NH3 and H2O, every part of the molecule have different attraction to charged particles." That's what I said: Electronegativity is specific to each element, not molecule, and I'd imagine it's only possible for pure covalent molecule structures to have an overall electronegativity. And yes, Primarygun is indeed from Hong Kong, China. However, I think his English is superb compared to the usual level of English-skills amongst the Chinese.
albertlee Posted October 31, 2004 Author Posted October 31, 2004 Again, for the 4th quote in my previous message, I dont really get the meaning for that,.. because why use "only" for NH3, while both NH3 and H2O have the same amount of lone pairs?
Gilded Posted October 31, 2004 Posted October 31, 2004 Yes, they do indeed have the same amount of lone pairs. However, oxygen's electronegativity is higher than nitrogen's, thereby making the specific lone pair section of the molecule more electronegative.
albertlee Posted October 31, 2004 Author Posted October 31, 2004 ??? Glided, they donot have the same amount of lone pairs!!! Oxygen has 6 electrons in the outer shell, and it needs another 2 electrons to form full outer shell. It share 2 electrons with 2 hydrogens, while those 2 hydrogen obtain full outer shell as well, so, 6-2= 4 4 electrons are not in valence between two obitals of different atoms, so.. there are 2 lone pairs.. For NH3, there is one lone pair... Any change on this? Albert
Gilded Posted October 31, 2004 Posted October 31, 2004 Whoopsie! I'm sorry, I just saw Primarygun saying so, thereby saying so myself. Should have thought about it for a second or so, then perhaps I would have realized this flaw. Sorry, sorry, sorry. Damn. :|
albertlee Posted October 31, 2004 Author Posted October 31, 2004 Does not matter, Glided!!! I think I know enough by now.... but dont know why the conversation becomes off-topic... Albert
Primarygun Posted November 1, 2004 Posted November 1, 2004 Yes, they do indeed have the same amount of lone pairs. However, oxygen's electronegativity is higher than nitrogen's, thereby making the specific lone pair section of the molecule more electronegative. Yes. My "only" means the degree of attraction since I stated the electronegativity after both atoms.lol:P I am wrong of telling the number of lone pair. I am not very familiar with those chapters which haven't been taught by my teacher.
Primarygun Posted November 3, 2004 Posted November 3, 2004 I was misleaded. I think I was correct. The strongest part is with a lone pair for each molecule.
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