Read the following questions carefully and answer them. 

“All the four quantum numbers of two electrons in an atom are not the same.” It is the law of — 

Which of the given metals cannot be extracted using smelting? 

Which of the following properties is not often present in organic compounds?

Gas is produced by the reaction of steam on iron?

If an alloy contains a metal mercury, what is it called?

It is easy to make stone by beating metals. Which property of the metal does it indicate?

is silica?

Which compound is formed when copper is burnt in air?