Argon was discovered by:(A) Rayleigh(B) Frankland and Lockyer(C) Jansen(D) Ramsay

The discovery of argon, a noble gas, is attributed to Lord Rayleigh (John William Strutt) and William Ramsay. They isolated argon from air in 1894.

Here's a brief explanation of how the discovery occurred:

Background: Before argon was discovered, scientists were investigating the composition of air and the various gases it contained.

Rayleigh's Work: Lord Rayleigh noticed that the density of nitrogen from chemical sources was slightly less than that of nitrogen obtained from the air. This led him to suspect that there was an unknown component in the air.

Collaboration with Ramsay: In collaboration with William Ramsay, they conducted experiments to isolate this gas. They used a method that involved removing oxygen and nitrogen from a sample of air.

Isolation of Argon: After the removal of these gases, they were left with a residual gas that did not react chemically. This gas was identified as argon, which was later confirmed to be a new element.

Conclusion: Therefore, the correct answer to the question is (A) Rayleigh, although it is important to note that Ramsay also played a crucial role in the discovery.

So, while Rayleigh is often credited with the discovery, Ramsay's contributions were essential as well. The most accurate answer based on the options given would be (A) Rayleigh.