metals and non metals class 10

electrorefining of metals can be used for refining of

• copper

• aluminum

• sodium

• calcium

silver articles become black on prolonged exposure to air. this is due to the formation of

• AgCN

• Ag2O

• Ag2S

• Ag2S and AgCN

iron is mixed with _______ to form stainless steel

• NI and C

• Al and C

• Ni and Cr

• NI and Cu

the process of electrolysis is used for obtaining such metals which are

• highly unreactive

• highly reactive

• all types of metals

• moderately reactive

when does phenolphthalein solution turn pink

• acid

• basic

• neutral

which one is not a neutral oxide

• N2O

• NO

• Na2O

• CO

which is the most reactive metal among the following

• copper

• zinc

• tin

• calcium

the elements which can turn litmus blue

• carbon and sulphur

• pottasium and magnesium

• sodium and carbon

• magnesium and sulphur

a yellow-colored powder X is soluble in carbon disulphide.it burns with a blue flame forming suffocating smelling gas which turns moist blue litmus red and is a major air pollutant. X maybe

• sulphur

• carbon

• argon

• nitrogen

which gas is present in the light bulb

• krypton

• argon

• xenon

• oxygen