First my apologies this was supposed to be out far earlier but I delayed it first because I was trying to organize the format (which is still evolving more on that later) and then because work and a promise I had forgotten about got in the way.
Now for those that do not know this is a series started by Translator a long time member who sadly is no longer with us. I decided to carry on his work both in memoriam and to continue what he began.
Before we jump into today’s element I have bit of an update into the format of this effort. For now diaries will be done Sunday, Wednesday and Friday at about 8pm EST. Mike Kahlow has generously offered to handle Fridays' and for now I will handle the other days. I know others expressed interest in writing either as guest writers or perhaps on a more regular basis and for those what I will ask is reply to my tip jar (assuming I set this up right, if not I’ll make a comment specifically for you all to reply to) . When you do please let me know if you are more interested in guest writing or something more regular. If there is enough people interested I might just make this a rotating set of writers but we will have to play this by ear.
Last bit of house keeping, I will eventually get all the diaries of the previous elements together as I know at least one person asked I just haven’t had the time to organize that. Now please follow me below as we explore silicon
Silicon has a fairly fascinating history, as some might know before the formulation of the periodic table one there were multiple attempts at organizing the known elements (and in fact at the end a diary on the history of the periodic table likely would be useful). These attempts largely revolved around naming conventions. For example metals ended in 'ium' like Germanium the element directly below it. Silicon too at one point was thought to be a metal and this can be seen in how some languages to this day refer to the element as "slicium". In the end though the name that was adopted was Silicon reflecting that it was similar to Born and Carbon. In terms of abundance it is the second most abundant element on earth (oxygen is the first) and makes up roughly 90% of the earth's crust in one form of silicate or another. As is often the case in groups (ie the columns of the periodic table) it is less reactive then the element above it but more reactive then the element below it.
Unlike the last element Silicon actually has some variance in the abundance of it's naturally occurring isotopes. There is Silicon-28 (92.2297%), Silicon-29 (4.6832%) and Silicon-30 (3.0872%) there are twenty other known isotopes that was not stable and of those only 2 have a half life greater then a couple seconds (Silicon-32 half life 170 years and Silicon-31 2.6217 hours). As seems to be the case with any unstable isotope there is some work done in Silicon dating though it seems to be mostly specialized applications such as in work on glaciers. The only other research use I know of for silicon is the use of Silicon-29 in NMR and EPR (most here probably know a little about NMR, the basic point of EPR is to study unpaired electrons it is rather similar to NMR only it is electrons and not the nucleus that is being studied).
Chemically speaking silicon is like carbon and considered tetravalent. However unlike carbon because it is a metalloid (metalloids are elements with mixed properties neither metallic nor nonmetallitc) it can actually form up to 6 bonds.
Commercially it is no exaggeration I think to say that silicon is extremely valuable to our modern world. Paradoxically though silicon generally does not generally have to be converted to a purified form in order to be used. In point of fact outside of electronics it's generally just not needed. Most probably are not aware of it because we depend on our electronics so much but the need for what is known as electronics grade Silicon (by the estimates I've read only about 20% of the total Silicon used in a year goes to electronics. Where does the rest go? Well the vast majority is actually used as ferrosilicon, an alloy of iron and silicon. Ferrosilicon acts as a reducing agent in metals which in the case of steel for example means acting as a sink for any oxygen in the molten steel. This is exteremely important as the amount of carbon and oxygen in steel must be tightly controlled in order to give the right type of steel. Silicon is also used with aluminum to improve aluminium casting, in point of fact as it is the most important additive for aluminium with it widely used in the process of making aluminium automotive parts. Silicon is also used in places where you might not expect it, silicon carbide for example is used as an abrasive and cutting tool as well as a high temperature semiconductor and in cermics for body armor and brake pads. Silicon is also used as Silicones (basically alternating silicon and oxygen bonds) which are then used in breast implants, mold making and mold release agents, waterproofing, high temperature grease and waxes. Actually a bit of trivia actually silly putty orginially was made by a combination of boric acid and silicone oil.
For silicon in electronics only about 5% of the world's production is used for monocrytaline silicon however this is the silicon that is used in intergrated circuits and solar cells. Thus despite being relatively small it has a huge level of importance. Generally speaking the remaining amount of electronics silicon is then used as semiconductor silicon. So why do we use silicon in our electronics? Well that could be a diary in and of itself but basically because silicon on it's own has a high electrical resistance. This resistance though can be modified by a process known as doping. Doping is introducing small amounts of other elements that allow for the conductivity of the element to be increased. Doping generally either involves "acceptors" or "donors". There is a lot of research done on semiconductors but again basically an "acceptor" (like boron in the case of silicon) create a 'hole' in the lattice. This hole then attracts another electron which creates another hole and so on. Thus charge is propigated by the filling and creation of holes. Donor types ( for example phosphorus in the case of silicon) the opposite happens, instead of creating a broken bond the element has an excess electron. This electron, because the lattice is almost pure silicon and silicon as a metalloid can freely move unbonded electrons around, can then be used to conduct charge.
However there are many many semiconductors what makes silicon widely used as semiconductor is that it can be a doped to be an acceptor or donor type, it is not too difficult to machine, that compartively it handles heat well before breaking down and of course there is the sheer abundance of silicon. All of these combined have made silicon the choice for mass produced semiconductors.
Biologically Silicone despite it's overwhelming ubiquitousness is not used as much (at least the research I've done on the topic indicates this). Mostly it is used by some sponges as a structural material. There has been some work done to try and have it designated a "plant benefical substance" by the Association of American Plant Food Control Officials based on some studies showing that silicon can improve drought resistance and cell structure but to my knowledge those studies are still in progress.