Period 6 element niobium, occurs in the minerals tantalite, columbite and coltan (a mix of columbite and tantalite). Tungsten, also known as wolfram, is a chemical element with the chemical symbol W and atomic number 74. The word "tungsten" comes from the Swedish language "tung sten" directly translatable to "heavy stone", though the name is "volfram" in Swedish to distinguish it from Scheelite, in Swedish alternatively named "tungsten". A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in
Melting-point depression which affects the cohesive energy and thermal properties of a nanostructure. Equation 7 gives a general shape corrected formula for the theoretical melting point of a nanoparticle based on its size and shape. formula_7 Where: c=materials constant The shape parameter is 1 for sphere and 3/2 for a very long wire, indicating that melting-point depression is suppressed in nanowires compared to nanoparticles. Past experimental data show that nanoscale tin platelets melt within a narrow range of 10 C of the bulk melting temperature. The melting point depression of these platelets was suppressed compared to spherical tin nanoparticles. Several nanoparticle melting