Superconductors and transition metals

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At very low temperature, some metals are superconductors:-

Normally, all metals have some electrical resistance - even really good conductors like copper.

That resistance means that whenever electricity flows through them, they heat up and some of the electrical energy is wasted as heat.

If you make some metals cold enough though their resistance disappears completely. The metal becomes a superconductor.

Without any resistance, none of the electrical energy is turned into heat, so none of it's wasted.

That means you could start a current flowing through a superconducting circuit, take out the batter and the current would carry on flowing forever.

Using superconducting wires you can make:-

Power cables that transmit electricity without any loss of power (loss-free power transmission).

Really strong electromagnets that don't need a constant power source.

Electronic circuits that work really fast because there's n resistance to slow them down.

But there's a catch - metals only start superconducting at less than -265 degrees Celsius. Getting things that cols is very hard and expensive, which limits the use of superconductors. Scientists are trying to develop room temperature superconductors.

Metals in the middle are the transition metals - a lot of everyday metals are transition metals like copper, iron, zinc, gold, silver, platinum but there are loads of others as well.

Transition metals and their compounds make good catalysts - iron is the catalyst used in the Haber process, nickel is useful for the hydrogenation of alkenes. the compounds of transition elements are colourful due to the transition metal ion they contain e.g Iron(II) compounds are usually light green, iron(III) compounds orange/brown and copper compounds are often blue.

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