Which of the following is not a pure substance and why?: brass, platinum, aluminum, sugar, or gold?
346921
Of those three are elements: Gold, Platinum, and Aluminium\n\nOne of them is a molecular compound: Sugar (each sugar molecule is the same, but is composed of many elements)\n\nOne of them is an alloy: Brass (composed of a melt of several metalic elements)\n\nReally depends of what your definition of "pure substance" is.
816755
Pottasium, Sodium, Iron ,  Lead, Copper, Silver, Gold.
15523
The higher the number the more gold, percentage wise\n\nGold is a precious metal that has been valued by people since ancient times. People use gold for coins, jewelry, ornaments, and many industrial purposes. Until recently, gold reserves formed the basis of world monetary systems. \n\nGold is a very soft metal when it is pure (24 Kt. is pure gold). Gold is the most malleable (hammerable) and ductile (able to be made into wire) metal. Gold is usually alloyed (mixed with other metals, often silver and copper) to make it less expensive and harder. The scientific abbreviation of gold is Au. \n\nThe purity of gold jewelry is measured in karats. Some countries hallmark gold with a three-digit number that indicates the parts per thousand of gold. In this system, "750" means 750/1000 gold (equal to 18K); "500" means 500/1000 gold (equal to 12K).\n\nTherefore 14K is better.
201939
a.)ionic b.)covalent c.)covalent d.)metallic
320001
the best of two is platinum in all cases\nbcos platinum is much rare and much beautiful metal than gold
981273
mercury\n\nmercury is a liquid metal\nand its composed of potassium, sodium, oxygen, argon, helium, nitrogen, Carbon dioxide, water, and hydrogen
621371
It is to stop reactions with organic products when cooking food. Brass is the term used for alloys of copper and zinc in a solid solution. It is more than 50% copper and from 5 to 20% zinc, in comparison to bronze which is principally an alloy of copper and tin. The copper in the alloy reacts with organic acids in the foodstuffs that can lead to food poisoning. The tin stops that from happening.
368567
You might be referring to brass, which has a density of 8.5 g/ml.\n\nBronze with 11% tin has a density of 8.1 g/ml.\n\n\nI would guess the brass, since it is more commonly used.
330110
Metalloids. They are "between" metals and non-metals.
767709
iron \nbronze\nbrass\nzinc (Jia Jing 15-20% zinc)\n\nMore details on Alloy Compositiob, see\nhttp://www.britishmuseum.co.uk/product.aspx?ID=1034\n\n"the coinage alloy from bronze to brass occured during the early part  of the 16th century, specifically during the later Hong Zhi period"
936278
Some metallic and some non-metallic.\nLike Silicium... it it shiny, just like metals, but doesn't conduct electricity, just like non-metals.\nOr Carbon... it is not shiny and doesn't react with acids, like non-metals, but conduct electricity, like metals.
93827
Diamond. It is pure carbon.
237020
Gold AU\nSilver AG\nLead PB\nCarbon C\nNickle NI\nIridium IR\nZR Zirconium\nCU copper\nLi Lithium
602913
No. White gold is an alloy of gold and silver. Therefore is less expensive than gold since it has a small percent of silver in it.\n(But be careful because some people refer to platinum as white gold. Platinum is far more expensive than gold)
1171259
Air is is mainly nitrogen  and oxygen with a mixture of other gases.\nmilk is proteins, fats, lactose, and various vitamins and minerals.\nBronze is various alloys of copper and tin and some bronze will contain other metals too.\nSugar is a sweet cystalline or powder derived from sucrose and lactose obtained mainly from sugar cane and sugar beets.\nSo in all technicality the answer would be E. no of the above.
237935
francium. mercury is technicaly not a metal, it just has a low melting point, low metling points do not make it unstable. if that were the case, then oxygen would be VERY unstable ITS ALREADY TURNED INTO VAPOR!!!
266285
That would be arsenic, As. It's found in the p-block of the periodic table as a metalloid. Group 15 (or group V, depending on the notation).