Hafnium

=__Hafnium__= By Junhyeong Park

1. Hafnium a. Mendeleev and Urbain predicted this element, and it was discovered by Bohr. b. It was discovered in1923.

2. Symbol: Hf, Atomic Number: 72, Atomic Mass: 178.49 a. ‘Hafnium’ came from word Hafnia, which is a Latin word that means Copenhagen, which is the capital city of Denmark. Bohr named this element as Hafnium because it was discovered in Copenhagen. The symbol of this element, Hf came from __H__a__f__nium.

3. It has 72 Protons, 72electrons, and 107 neutrons.

4. It was found in the Earth, and the Sun’s atmosphere. Hafnium is solid.

5. Physical Facts a. Melting Point: 2,150°C/3902°F/ 2423.15K. b. Boiling Point: 5400°C/9752°F/5673.15K. c. Density: 13.31g/cm3 d. Abundance in the Earth’s crust: 3.3 parts per million by weight, 0.4 parts per million by moles

6. Hafnium is used to make control rods of nuclear weapons, alloys, micro-processors, incandescent lamps, the electrode of plasma cutting, and weapons with X-ray triggering mechanisms.

7. Interesting facts a. 1g of Hafnium can create 50kg of TNT fire force. Using this characteristic, a lot of countries are developing their own hafnium bombs. 50kg of Hafnium can destroy 197684acre. (800km2) b. Chemically, it’s similar to zirconium. <span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">c. At high temperature, it reacts with carbon, boron, silicon, sulfur, and nitrogen.

<span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.5in; text-indent: -0.25in;">8. Sources <span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">a. [|www.chemicool.com] <span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">b. periodic.lanl.gov <span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">c. 100.naver.com <span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">d. [|www.wikipedia.org] <span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">e. [|www.webelements.com]

=<span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;"> = =<span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;"><Hafnium> = =<span style="font-family: 'Arial','sans-serif'; font-size: 11.5pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;"> = =<span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif;"><Structure of protons and electrons of Hafnium> = = =