#1 Brass gets discoloured in air because of the presence of which of the following gases in air?
Brass gets discolored in air because of the presence of Hydrogen sulphide. Reason :- It is because the presence of mixture of hydrogen and sulphide and brass is a type of thing which has a color very light and mixture is non temperature (hot and cold type of temperature) so it gets discolored.
#2 Which of the following metals remain in liquid for under normal conditions?
Mercury is the only metal that is a liquid at normal temperatures and pressure. But, why is mercury a liquid? What makes this element so special? Basically, it’s because mercury is bad at sharing… electrons, that is.
#3 Potassium Permanganate is used for purifying drinking water, because
Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.
#4 Which of the following is an element?
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable form, but diamond almost never converts to it.
#5 Which of the following is a non metal that remains liquid at room temperature?
The chemical element with the atomic number 35, Bromine is a non metal that remains liquid at room temperature. Mercury also remains liquid at room temperature but it is a metal. Bromine is the third lightest halogen.