Tungsten is classified as a transition metal. Known by the chemical symbol W, from its alternative name Wolfram, this element is a relatively rare metal found naturally in the Earth’s crust. It is notable for its high density, comparable to that of gold and uranium, and its robustness. The properties of tungsten allow it to perform in high-stress environments where many other metallic elements would fail.
Defining the Transition Metals Category
The classification of an element as a transition metal is based on its electron structure. Transition metals are located in the central d-block of the periodic table, spanning Groups 3 through 12. Their defining characteristic is the ability to form at least one ion that possesses a partially filled d subshell. This incomplete orbital structure is responsible for the diverse chemical behavior seen in this group of elements.
The presence of available d-orbitals allows transition metals to exhibit multiple possible oxidation states, unlike the metals in the s-block (Groups 1 and 2). This variability in charge enables them to form a wide range of compounds with distinct chemical properties. These metals also have high melting points, high densities, and the ability to form colored compounds.
Tungsten’s Specific Chemical Identity
Tungsten, with an atomic number of 74, resides in Group 6 and Period 6 of the periodic table, placing it squarely within the d-block elements. Its electron configuration confirms its status as a transition metal, specifically because its valence electrons occupy both the 6s and 5d orbitals. The configuration is written as \([Xe] 4f^{14} 5d^4 6s^2\), which includes a partially filled 5d subshell.
This orbital arrangement allows tungsten to exhibit a wide range of oxidation states from +2 up to +6. The hexavalent state (+6) is the most common and stable in its compounds. For instance, tungsten forms compounds where it has lost its two 6s electrons and four 5d electrons.
Observable Physical Characteristics
Tungsten is renowned for its extreme physical properties, which are a direct consequence of its strong metallic bonding. It possesses the highest melting point of any pure element, reaching \(3,422^\circ C\) (\(6,192^\circ F\)). This thermal stability is why it is often referred to as a refractory metal, meaning it retains its strength at very high temperatures.
The element also exhibits a high density, measuring approximately \(19.25 \text{ g/cm}^3\). This places it among the densest naturally occurring elements, nearly twice as dense as lead. While pure polycrystalline tungsten is intrinsically hard and brittle at room temperature, its strong atomic structure gives it the highest tensile strength of any metal above \(1,650^\circ C\).
Primary Industrial Applications
The properties of tungsten make it indispensable across several industries. Its melting point makes it the material of choice for high-temperature applications, such as the filaments in incandescent light bulbs, which operate at white-hot temperatures without melting. It is also used in heating elements for high-temperature furnaces.
Tungsten’s hardness is leveraged in the production of tungsten carbide, a ceramic composite used in high-speed cutting tools, drill bits, and mining equipment. These tools are able to machine hardened steel with minimal wear due to the material’s superior abrasion resistance. The metal’s high density is utilized in applications that require significant mass in a confined space, such as counterweights in aircraft and race cars, as well as in radiation shielding.