XI Note-making -

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 Class-XI

Q.Read the following extract carefully and make the notes with the help of the clues given below.

Note-making -(03 Marks)

Naturally occurring platinum and platinum rich alloys have been known for a long time. The Spaniards named the metal 'platina' or little silver, when they first encountered it in Columbia. The platinum group metals are rhodium, ruthenium, palladium,osmium, iridium and platinum. Of these, platinum is the most important. These metals are very similar in many ways and are extremely rare.

     On average, there is only a gramme of ruthenium in each tonne of rock and barely a gramme of rhodium in over a 1000 tonnes of rock! Platinum's wear and tarnish resistance characteristics are well suited for making fine jewellery. Other distinctive properties include- resistance to chemical attack, excellent high temperature characteristic and stable electric properties. These metals are uniquely durable and can be used extremely efficiently- meaning that very little goes a very long way. When recycled, over 96% can be recovered. The platinum group metals - or PGMS - plays an important role in our everyday life, for they are used in so many things from fountain pens to aircraft turbines. In fact, one in four of the goods manufactured today either contain one or the other of these metals. The catalytic converter- a pollution control device - is the largest application of platinum group metals.

Ans- 

Title - Platinum Group of Metals


1. First encountered: .............in Columbia.


2. Platinum group metals include: 

iridium and..................


3. Nature: ...........


4. Availablity: .........


5.Distinctive Properties:

..............

..............

................

................

6.Platinum group metals used in:

..............


Ans-

1. First encountered: The Spaniards named the metal 'platina' or little silver, when they first encountered in Columbia.

2. Platinum group metals include: 

rhodium, ruthenium, palladium,osmium, iridium and platinum.

3. Nature: similar in many ways and are extremely rare.

4. Availability: Only a gramme of ruthenium in each tonne of rock and barely a gramme of rhodium in over a 1000 tonnes of rock.

5.Distinctive Properties:

wear and tarnish resistance. 

resistance to chemical attack.

durable, long lasting.

When recycled, over 96% can be recovered.

6.Platinum group metals used in:

fountain pens to aircraft turbines. In fact, one in four of the goods manufactured today either contain one or the other of these metals. The catalytic converter- a pollution control device. 

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