"Hafnium and Zirconium are in some ways the same, But Hafnium's used in nuclear control and has a different name."	Hafnium By Alana Mill Valley Middle School
	Properties The 5 W's Uses Hafnium and Zirconium Interesting Facts Bibliography Glossary	Zirconium Ring
The Who, What, Where, When and Why Who: Georg van Hevesy and Dirk Coster What: The element Hafnium, a silvery metal Where: In Copenhagen, Denmark. The name Hafnium comes from the Latin name for Copenhagen. When: 1923 Why: The discovery of Hafnium was delayed because of its great similarity to Zirconium. Like zirconium, is used in some important things, such as nuclear control rods.		Hafnium and Zirconium Hafnium and Zirconium are two of the most difficult to separate of all the elements. Both are in Group 4 and have similar properties. In fact, most zirconium minerals contain 1-5% hafnium! Both elements can spontaneously ignite when finely divided and both are used in vacuums. Because the two elements are so similar, the discovery of hafnium came later than it might have, had it not been so similar to zirconium. Want to learn more about zirconium?
	72	Hafnium, in a very small amount, is found in the sun.
Uses Hafnium, because of its ability to absorb neutrons, is used in nuclear control rods and in nuclear submarines. It is used in vacuum cleaners. All three of the above uses are in elemental form. It is also used in gas filled and incandescent lamps. It has been successfully alloyed with iron, titanium, niobium and tantalum and appears as a compound in nature.	Properties chemical symbol Hf atomic number 72 group 4 atomic mass 178.49 protons 72 electrons in uncharged atom 72 most common isotope 106 neutrons number of electrons per energy level 2, 8, 18, 32, 10, 2 state at room temperature solid color silver	Interesting Facts Hafnium can spontaneously ignite in the finely divided form. makes up .00000001% of the sun can absorb neutrons easily in many languages Hafnium is "Hafnium" cost per pound is $100-$500, depending on the purity
Bibliography Todd, Robert W. Holt Science and Technology, Physical Science. Holt, Rinehart and Winston: Austin, Texas. 2001. Periodic Table of Elements Wall Chart. American Chemical Society. Chemicool Periodic Table Environmental Chemistry Periodic Table Periodic Table of the Elements Images found at: http://images.google.com/imgres?imgurl=pearl1.lanl.gov/periodic/images/submarine.gif &imgrefurl=http://pearl1.lanl.gov/periodic/elements/72.html&h=146&w=289&prev =/images%3Fq%3Dhafnium%26svnum%3D10%26hl%3Den http://www.flamingtext.com http://www.musicofthesoul.com/images/fire.jpg http://www.lge.ca/product/household/images/vu-101c.gif http://www.goldcityjewelry.com/Hawaiian-Jewelry/hawaiin41.jpg http://www.rit.edu/~dabdis/tech/vocab/hafnium.gif http://www.cirkits.com/solar/sun.gif		Glossary isotopes- atoms of the same element that have a different number of neutrons. atomic mass- the weighted average mass of the protons and neutrons (electrons weigh almost nothing). alloy- a solid solution of metals or nonmetals dissolved in metals.