will coal b considered an element coz it has high % of carbon???
125385
Nope, an element is a pure.  Coal is a a mixture, and although  carbon composes a high percentage, the carbon is not pure.  It is primarily present as a part of a carbon based compound.
188615
Carbon Dioxide is always a product of combustion, never a reactant.  Adding CO2 to a fire/explosion would only every suppress the reaction, not promote it (according to LeChatelier's principle).  The only "explosions" you'll get with CO2 would be pressure based (release of pressurized gas), not chemically based.
676564
This question would have been much easier if the specific heat capacity of coal were known!\n\nNevertheless, let us model the coal to be anthracite of composition 85% graphite and rest 15% water. \nSo the s.h.c = 0.85*0.17 + 0.15*1 = 0.2945 cal/g-°C\nwhich gives heat required as 0.2945*(220-20)*5000 = 294500 cal\n=294500*4.184=1,232,188 J\nSo it seems the answer is C\n\nTo check this we can back calculate the s.h.c(specific heat capacity) using ans C which gives the graphite content in coal as 78.8% (quite realistic)\nUsing ans D the s.h.c is greater than for water(not physically possible) \nAnd A and B can be eliminated simply by order of magnitude analysis.\n\nIt seems most likely that C is the ans.
508007
pretty much all elements are created in stars, the actual process is very confusing thankfully wikipedia is a better expaliner than i ----> http://en.wikipedia.org/wiki/Nuclear_fusion\nO2 is important because it helps us create lots of energy from glucose
5425
Yes and No...\n\nAll Organic Compounds contain Carbon, but not all compounds containing Carbon are Organic.\n\nas quoted from my source, listed below...\n\n"An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with the exception of carbides, carbonates, carbon oxides and gases containing carbon.The study of organic compounds is termed organic chemistry. Many of these compounds, such as proteins, fats, and carbohydrates (sugars), are also of prime importance in biochemistry.\n\nThe dividing line between organic and inorganic is contended and historically arbitrary; generally speaking, however, organic compounds are defined as those compounds which have carbon-hydrogen bonds, and inorganic compounds, those without. Thus carbonic acid is inorganic, whereas formic acid, the first fatty acid, is organic, although it could as well be called "carbonous acid" and its anhydride, carbon monoxide, is inorganic"
349774
Because there will always be interactions between all the elements in a compund except for a bridging ligand, we can asusme that we need to take into account the charge on each atom. \n\na element in group 2 is always +2\na element in group 4 is +2,3,4\nOxygen is is -2\n\nknowing we have a neutral charge we can immedialty eliminate C and as we know that we must use all of our atoms the only answer that makes sense is D
462188
I believe graphite in a nonmetallic allotrope of carbon. However, it is a condutor of electricity.
49890
Coal is hard to transport, you need large rail system to move the coal \nfrom place to place. \n\nAs most coal is extracted from the earth by strip-mining, this can cause serious harm and devastation to the land. \n\nStrip mining as well as underground mining, another way to extract coal, leaves behind large quantities of waste rock\n\nAcid leaching from the wastes contaminates streams and rivers.\n\nDisposal problem of ash that is created when coal is burned\n\nThe sulfur dioxide emitted when coal is combusted is primary cause of acid rain\n\nThe carbon dioxide created in the atmosphere during the burning of coal has the potential to change the earths climate creating global warming
516025
CO2 and H2SO4\n\n"metal" belongs to group IA, IIA, and B\n\nNa is IA\nK is IA
676879
Types of Coal\nWe use the term "coal" to describe a variety of fossilized plant materials, but no two coals are exactly alike. Heating value, ash melting temperature, sulfur and other impurities, mechanical strength, and many other chemical and physical properties must be considered when matching specific coals to a particular application. \n\nCoal is classified into four general categories, or "ranks." They range from lignite through subbituminous and bituminous to anthracite, reflecting the progressive response of individual deposits of coal to increasing heat and pressure. The carbon content of coal supplies most of its heating value, but other factors also influence the amount of energy it contains per unit of weight. (The amount of energy in coal is expressed in British thermal units per pound. A BTU is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.) \n\nAbout 90 percent of the coal in this country falls in the bituminous and subbituminous categories, which rank below anthracite and, for the most part, contain less energy per unit of weight. Bituminous coal predominates in the Eastern and Mid-continent coal fields, while subbituminous coal is generally found in the Western states and Alaska. \n\nLignite ranks the lowest and is the youngest of the coals. Most lignite is mined in Texas, but large deposits also are found in Montana, North Dakota, and some Gulf Coast states. \n\nAnthracite\nAnthracite is coal with the highest carbon content, between 86 and 98 percent, and a heat value of nearly 15,000 BTUs-per-pound. Most frequently associated with home heating, anthracite is a very small segment of the U.S. coal market. There are 7.3 billion tons of anthracite reserves in the United States, found mostly in 11 northeastern counties in Pennsylvania. \n\nBituminous\nThe most plentiful form of coal in the United States, bituminous coal is used primarily to generate electricity and make coke for the steel industry. The fastest growing market for coal, though still a small one, is supplying heat for industrial processes. Bituminous coal has a carbon content ranging from 45 to 86 percent carbon and a heat value of 10,500 to 15,500 BTUs-per-pound. \n\nSubbituminous\nRanking below bituminous is subbituminous coal with 35-45 percent carbon content and a heat value between 8,300 and 13,000 BTUs-per-pound. Reserves are located mainly in a half-dozen Western states and Alaska. Although its heat value is lower, this coal generally has a lower sulfur content than other types, which makes it attractive for use because it is cleaner burning. \n\nLignite\nLignite is a geologically young coal which has the lowest carbon content, 25-35 percent, and a heat value ranging between 4,000 and 8,300 BTUs-per-pound. Sometimes called brown coal, it is mainly used for electric power generation
49248
Charcoal = activated carbon solid\nit is an active surface and reacts with almost anything. We use them in gloveboxes to allow air to circulate and not poisoning ourselves.\nEventually the charcoal wil become deactivated as there are no more active sites
187793
Coal is our most abundant fossil fuel resource. Coal is a complex mixture of organic chemical substances containing carbon, hydrogen and oxygen in chemical combination, together with smaller amounts of nitrogen and sulfur. This organic part of coal has associated with it various amounts of moisture and minerals.\n\nI took this definition from the first site. It also has a links to a lot of realted information and details about coal.\nThe wiki also has good facts. have included the link. If you want the details for a child's project have included a children's site link.\nAll three sites are good.
529775
Many materials can react with ozone to form oxygen as a by-product.  Most all are reducing agents.  A more definitive answer rests on how you are using the term "element".  If you are using it the periodic table sense then your answer would include many of the metals capable of being oxidized.
249978
Depends on the metal. Most metals generally become brittle. Iron on the addition of Carbon hardens. You may say option 2.
599459
since a "certain" soft metal on burning produces lime  lime cannot be an element . hence the answer is 'c'\nanswer : 'c'\n  note: the soft metal is calcium
313980
well i think it is option B.....\ncoz..bronze is mixture not compound ..of the folowing elements...coz we can separte the elements which made it...coz in cpomunds elements lost their individual charactersitics..but in mixture they retian them...\nand zinc ,tin,copper r elements not compunds..coz compunds made up of 2 ..to more elemnts.while zince tin,cooper r themsleves are elemnts coz these r have standards at.no and wt.n presents in periodic table..which show elements
231184
Carbon is a chemical element in the periodic table that has the symbol C and atomic number 6. An abundant nonmetallic, tetravalent element, carbon has several allotropic forms, including diamond and graphite. Carbon occurs in all organic life and is the basis of organic chemistry. This nonmetal also has the interesting chemical property of being able to bond with itself and a wide variety of other elements, forming nearly 10 million known compounds.