Visual and light scattering spectrometric method for the detection of melamine using uracil 5'-triphosphate sodium modified gold nanoparticles.

See more Gold products. Gold (atomic symbol: Au, atomic number: 79) is a Block D, Group 11, Period 6 element with an atomic weight of 196.966569. The number of electrons in each of Gold's shells is 2, 8, 18, 32, 18, 1 and its electron configuration is [Xe]4f¹⁴² 5d¹⁰ 6s¹. The gold atom has a radius of 144 pm and a Van der Waals radius of 217 pm. Gold was first discovered by Early Man prior to 6000 B.C. In its elemental form, gold has a metallic yellow appearance. Gold is a soft metal and is usually alloyed to give it more strength. It is a good conductor of heat and electricity, and is unaffected by air and most reagents. It is one of the least reactive chemical elements. Gold is often found as a free element and with silver as a gold-silver alloy. Less commonly, it is found in minerals as gold compounds, usually with tellurium.

See more Phosphorus products. Phosphorus (atomic symbol: P, atomic number: 15) is a Block P, Group 15, Period 3 element. The number of electrons in each of Phosphorus's shells is 2, 8, 5 and its electronic configuration is [Ne] 3s² 3p³. The phosphorus atom has a radius of 110.5.pm and its Van der Waals radius is 180.pm. Phosphorus is a highly-reactive non-metallic element (sometimes considered a metalloid) with two primary allotropes, white phosphorus and red phosphorus its black flaky appearance is similar to graphitic carbon. Compound forms of phosphorus include phosphates and phosphides. Phosphorous was first recognized as an element by Hennig Brand in 1669 its name (phosphorus mirabilis, or "bearer of light") was inspired from the brilliant glow emitted by its distillation.

See more Sodium products. Sodium (atomic symbol: Na, atomic number: 11) is a Block D, Group 5, Period 4 element with an atomic weight of 22.989769. The number of electrons in each of Sodium's shells is [2, 8, 1] and its electron configuration is [Ne] 3s¹. The sodium atom has a radius of 185.8 pm and a Van der Waals radius of 227 pm. Sodium was discovered and first isolated by Sir Humphrey Davy in 1807. In its elemental form, sodium has a silvery-white metallic appearance. It is the sixth most abundant element, making up 2.6 % of the earth's crust. Sodium does not occur in nature as a free element and must be extracted from its compounds (e.g., feldspars, sodalite, and rock salt). The name Sodium is thought to come from the Arabic word suda, meaning "headache" (due to sodium carbonate's headache-alleviating properties), and its elemental symbol Na comes from natrium, its Latin name.