Luminal Posted June 13, 2007 Posted June 13, 2007 I have scanned the web, read chemistry books, and so forth, and I cannot figure out these Chemistry questions for the life of me, although they are probably very simple to answer for others. Unfortunately, I took Biology in college and never had a chance to ask these to a professor. Also, I think I have a mental block when it comes to anything involving particles. 1) Why can't Boron accept 5 other electrons in covalent bonding, as Carbon accepts 4, thereby making it an even better candidate than Carbon for the basis of complex molecules and living matter? 2) Why do heavier elements have more trouble forming complex bonds? Silicon has almost the exact same valency as Carbon, but when I walk out my back door, I don't see Silicon-based organisms roaming around with the Carbon-based ones. And/or why don't Phosphorus and Sulfur act the same way as Nitrogen and Oxygen? I think I'm basically confused about how the mass changes the reactivity when nothing else changes (such as valency)... because I didn't figure it did. 3) Oh, and most importantly, what causes the Octet Rule? It just seems Chemistry has far too much complexity, an inconveiable amount, for something that springs from the interaction of the exact same 3 particles in every instance: up quark, down quark, electron, or more directly, proton, neutron, and electron. It's not as if different elements used different particles. They are all the same! All of this just makes me wonder if there are dimensions or universes where their Periodic Tables are based upon 4 or 5 common particles, rather than 3. I shudder to think about the poor students in Chemistry class in those realities.
foodchain Posted June 13, 2007 Posted June 13, 2007 I have scanned the web, read chemistry books, and so forth, and I cannot figure out these Chemistry questions for the life of me, although they are probably very simple to answer for others. Unfortunately, I took Biology in college and never had a chance to ask these to a professor. Also, I think I have a mental block when it comes to anything involving particles. 1) Why can't Boron accept 5 other electrons in covalent bonding, as Carbon accepts 4, thereby making it an even better candidate than Carbon for the basis of complex molecules and living matter? 2) Why do heavier elements have more trouble forming complex bonds? Silicon has almost the exact same valency as Carbon, but when I walk out my back door, I don't see Silicon-based organisms roaming around with the Carbon-based ones. And/or why don't Phosphorus and Sulfur act the same way as Nitrogen and Oxygen? I think I'm basically confused about how the mass changes the reactivity when nothing else changes (such as valency)... because I didn't figure it did. 3) Oh, and most importantly, what causes the Octet Rule? It just seems Chemistry has far too much complexity, an inconveiable amount, for something that springs from the interaction of the exact same 3 particles in every instance: up quark, down quark, electron, or more directly, proton, neutron, and electron. It's not as if different elements used different particles. They are all the same! All of this just makes me wonder if there are dimensions or universes where their Periodic Tables are based upon 4 or 5 common particles, rather than 3. I shudder to think about the poor students in Chemistry class in those realities. Perhaps is the reason a hawk is a hawk and an eagle is an eagle. Chemical species are natural kinds, in that they just are. Now looking at a great many rules per say in chemistry, there is always some exception somewhere. What I gather from that, and looking at the periodic table and the "evolution" if you will of chemical species, they have different behaviors. For instance, looking at isotopes, what difference does a missing neutron or two make when its simply electrons that denote in major chemical reactivity of an element? Well it does have an impact on reaction mechanisms, so what do you think now? Even if the difference is by one electron, its going to have an impact on the behavior of the element in regards to say boding or structure. Another thing to look at in regards to evolution of life, is that the primary elements that make up life, happen to be some of the most abundant elements in the universe for instance. I think a weirder idea is to imagine what evolution would be like if most of the crusts surface area on earth had the properties related to or happened to be composed of teflon:D You also have to look at physical properties, in that I don’t know how well cells would operate per say if they had steel for a cell wall, now not to say that such cant come about ever. I mean we do have some broad variance in biochemistry on earth, simple example being organisms that thrive in volcanic sea vents, or really in ecologies that previous to discovery were really not thought possible by a great many and when found managed to shock even more. The environments of sea vents are deadly to all other known life on earth, and to view such as a human requires a piece of engineering that’s rather sturdy to say the least.
jdurg Posted June 14, 2007 Posted June 14, 2007 There actually are some pretty detailed explanations to all of the questions that have been asked, and many of them involved math and physics more than chemistry. To answer them all here in one post would flood you with facts and theories and information and make your brain cry.
agaubr Posted June 16, 2007 Posted June 16, 2007 It ow appears the best model suggest all things are made up of the fundamental moiety called a string and follows "M Theory or The Theory of Everything". In response to your questions: 1) The octet rule suggests the most number of electrons to occupy an outside valence shell is 8 which works pretty good for the group A elements although their are exceptions. Many exceptions are found in the group B series. The reason for the 8 is you are filling the s and p orbitals for the group A so you can only have 8 electrons. 2) Boron does not pick up the five electrons due to energy considerations and driving the system to a higher energy state and thus create an instability. But using the three electrons it has Boron does do some very unique things and creates some very interesting compounds and bonding patterns such as spreading two electrons over three atoms to yield a 2/3 bond. 3) The use of more complex atoms versus carbon to create life seems to a tough one to answer except to say it is easier to do it this way in our current system of physical reality. My simple answer is energy again. the driving force to do something is to produce a system which has lower energy than reactants so you get a downhill energy plunge. To go uphill will require some complex happenings and then there must be a reason for this to be stabilized so can exist. Good questions. Sometimes these questions are buried in philosophy more so than science. agaubr. agaubr.
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