Question 1 :
Brass gets discoloured in air because of the presence of which of the following gases in air?
Question 2 :
Which of the following is a non metal that remains liquid at room temperature?
Question 3 :
Chlorophyll is a naturally occurring chelate compound in which central metal is
Question 4 :
Which of the following is used in pencils?
Question 5 :
Which of the following metals forms an amalgam with other metals?