9.What happens electrically to the insulating layer of a silicon-based transistor as it becomes smaller (thinner)? As the insulating layer of silicon dioxide becomes thinner, it eventually reaches a thickness that no longer can insulate or prevent electrons from leaking between the top and bottom conducting layers.10.How has the problem mentioned in Q#9 been overcome, chemically speaking?Adding the compound, Hafnium oxide to the insulating layer allows thinner transistors without having the electron leakage of silicon dioxide.11.What are the separate functions of gold and zirconium oxide in converting volatile organic molecules or compounds (VOCs), such as formaldehyde, into carbon dioxide (CO2) and water (H2O)?The gold acts as a catalyst to the reaction, while the zirconium oxide is merely a structural element that holds the gold.12.What additional “ingredient” is needed besides gold to convert VOCs to carbon dioxide and water?There must be a form of energy, in this case, visible light. The blue end of the visible spectrum is most energetic and therefore the most productive while the entire spectrum of sunlight is less efficient (64% reduction in the concentration of formaldehyde using just blue light vs. 8 % reduction using sunlight’s spectrum).Graphite Versus Diamond: Same Element but Different Properties1.What are the modern day uses of charcoal, an amorphous form of carbon?Charcoal is used in briquettes for outdoor grilling and barbecues, in water filters to remove bacteria, and in the form of sticks and powder used as drawing materials in artwork.2.What are some uses of graphite?A mixture of clay and graphite is the “lead” in pencils. Graphite is also used as a lubricant byadding it to oils and greases and as a molding material in glass manufacture.8
3.List some of the contrasting properties of graphite and diamond.Diamond is the hardest natural substance known while graphite is one of the softest. Diamond does not conduct electricity while graphite is a good conductor of electricity.Diamond is the ultimate abrasive while graphite is a good lubricant.4.What is the difference in bonding between diamond and graphite?In diamond, each carbon is covalently bonding to four other carbon atoms while in graphite each carbon atom is covalently bonded to only three carbon atoms.5.Describe the shape of the lattice formed in diamond and in graphite.The lattice in diamond is a three-dimensional tetrahedral lattice. The lattice in graphite is a two dimensional sheet-like lattice with the carbon atoms arranged in a hexagonal pattern.6.What are the allotropes of carbon called?The allotropes of carbon are diamond, graphite, and fullerenes.7.Describe the process by which diamonds found in remnants of volcanic eruptions are formed.
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- Fall '16
- ased desaq