Which of the following gases is responsible for discolouration of brass in air?

Which of the following is the heaviest metal?

In which of the following metals is the speed of sound the fastest?

Duralumin is an alloy of copper and

Plumbism is a condition due to the poisoning effect of

Who among the following on April 1, 2014 adopted the Consumer Price Index (CPI) as the key measure of Inflation?