MEDIUM
7th CBSE
IMPORTANT
Earn 100
Pyrex or Borosil glass is used for making laboratory apparatus, whereas crown glass is used in the manufacture of optical instruments. Give a reason for the same.
Important Questions on Chemistry in Daily Life
HARD
7th CBSE
IMPORTANT
A nonmetal X is lustrous, insoluble in water but soluble in alcohol, when it reacts with another metallic element Y, it forms a substance Z which are used in cloud seeding or artificial rain. Identify X, Y and Z. What are the advantages of artificial rain? Is there any substances other than Z that can be used for artificial rain? If so, what are they?
HARD
7th CBSE
IMPORTANT
Metal 'X' is highly malleable, ductile and a good conductor of electricity. Metal 'Y' burns with a white dazzling flame and possesses a silvery white lustre. 'X' and 'Y' are major and minor components in 'Z'. 'Z' is used for the manufacture of aircraft frames. Identify X, Y and Z.
