Tungsten Unveiled: Density, Reactions, and Hands-On Demonstrations | Periodic Videos

Video overview

Periodic Videos investigates tungsten, its exceptional density, and its role in everyday materials through a collection of engaging demonstrations. The film covers density comparisons, tungsten carbide applications, and a variety of chemical experiments that reveal tungsten chemistry in action.

• Tungsten is extremely dense and physically heavy for its size
• Demonstrations compare a kilo of tungsten with a liter of water to visualize density
• Reactions include tungsten with mercury, bromine, and sodium to illustrate oxidation and color changes
• Polyoxometallates containing tungsten demonstrate color changes due to electron transfer

Overview

This video from Periodic Videos delves into tungsten, its position in group 6 of the periodic table, and why it is such a dense metal. The host explains that density increases down a group as atoms get heavier, yet the atomic size does not grow much, allowing tight packing and high density. Tungsten’s symbol W comes from Wolfram, its German name, and the segment touches on tungsten’s ubiquity from phone components to tungsten carbide tools.

Key Properties and Everyday Uses

The discussion emphasizes tungsten’s exceptional density, its use in everyday objects, and the reasons for its popularity in industry. The video also notes the tungsten carbide tips in drill bits and the way tungsten’s high density affects demonstrations about volume and weight comparisons with water.

Hands-On Demonstrations

Several experiments showcase tungsten’s properties. A kilo of tungsten is weighed and compared to a liter of water, illustrating the vast difference in volume despite similar mass. The video also explores buoyancy experiments to compare tungsten with lighter metals like molybdenum, revealing how density influences sinking and floating behavior in liquids like mercury. A safety note and the role of technicians in executing on-the-fly demonstrations are highlighted, underscoring the importance of skilled support in experimental science.

Exploring Tungsten Chemistry

The narrative extends to chemical reactions involving tungsten, including reactions with bromine to form tungsten bromides and demonstrate how bromine can displace oxygen in air. The use of tungsten oxide in demonstrations and the color changes observed during heating are discussed, along with considerations about sealing reaction tubes to prevent air ingress. A segment introduces polyoxometallates, clusters containing tungsten atoms, and explains how UV light can drive reactions that change tungsten's oxidation state, producing vivid blue colors due to electron hopping within the cluster.

Safety, Technology and Community

The host praises technicians and notes the Gatsby Foundation’s sponsorship of a new gallery at the Science Museum in London. The video closes with appreciation for the broader science community, the importance of hands-on demonstrations, and a nod to ongoing tungsten chemistry research.