PT: Periodic Table


Core Vocabulary Quizlet

Group 1 Alkali Metals
Brianiac Video showing Group 1 metals reacting with H2O.

According to Wikipedia, the rubidium and cesium explosions shown in the video above were faked! See below for the details...

Nevertheless, I think that the video does do a good job of showing the affect that an element's period has on the energy of the chemical reaction, and it's a lot of fun, so it is still worth watching!

From Wikipedia:

Forged results

At least one faked result has surfaced (the alkali metal experiments).[3]

One experiment conducted by Brainiac aimed to illustrate periodic trends in the alkali metal series. It showed the violent reactions of metallic sodium and potassium with water, in which the hydrogen produced subsequent explosions, and intended to demonstrate the even greater reactivity of rubidium and caesium by dropping them into a water-filled bathtub. However, the reaction was not particularly spectacular, and the crew substituted explosives for the alkali metals. This is clearly visible in the footage, in which an "explosives" sign can be seen on the premises, and an exploding cloud of hydrogen gas, which one would expect in an alkali metal reaction with water, was not visible.[4]

The Brainiac staff have admitted that the explosions had been faked.[3][5] According to Tom Pringle, Brainiac's "Dr Bunhead", very little occurred in the real reaction of caesium and water, as the large volume of water over it drowned out the thermal shock wave that should have shattered the bathtub. The crew decided to set up a bomb in the tub and use that footage to generate the explosion.[3]

Similar experiments with caesium or rubidium have been repeated; these include Popular Science columnist Theodore Gray's experiments,[6] the "Viewer Special Threequel" episode of MythBusters, and an attempt made as part of the Periodic Table of Videos series created by several faculty members at the University of Nottingham.[7] In no case were the rubidium and caesium reactions nearly as violent or explosive as depicted on Brainiac.

However, a much earlier and more successful attempt was shown on British TV in the 1970s as part of the Open University programmes. Here, rubidium splatters around as soon as it hits the water's surface (with some parts sinking and creating more violent bangs). Caesium, on the other hand, does create an explosion and destroys the apparatus, mainly due to the fact that the metal sinks well into the water and creates a large "cone" of hydrogen gas before it ignites and explodes. This video is available online at The Open University.[8]


Enrichment Resources!

Chemistry Videos:

Cool online Periodic Tables to explore!

Periodic Table Trends
History of the Periodic Table
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David E. Lawrence,
Feb 13, 2013, 8:21 AM
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