(b) heating above 100°C
     (c) passing an electric current
     (d) just keeping it for 10 minutes
Ans: (b)
263. Contact lenses are made from [CDS 2011]
     (a) polyvinyl chloride
     (b) polystyrene
     (c) Lucite
     (d) Teflon
Ans: (c)
264. Which one among the following metals is used for making boats because it does not corrode by seawater? [CDS 2011]
     (a) Tungsten
     (b) Nickel
     (c) Antimony
     (d) Titanium
Ans: (d)
265. Which one among the following is a strong smelling agent added to LPG cylinder to help in the detection of gas
     leakage? [CDS 2011]
     (a) Ethanol
     (b) Thioethanol
     (c) Methane
     (d) Chloroform
Ans: (b)
266. Which type of glass is used for making glass reinforced plastic? [CPO (SI) 2010]
     (a) Pyrex glass
     (b) Flint glass
     (c) Quartz glass
     (d) Fibre glass
Ans: (c)
267. Identify the metal which is non-toxic in nature [SSC(10+2) 2010]
     (a) Chromium
     (b) Gold
     (c) Cadmium
     (d) Cobalt
Ans: (b)
268. A powerful eye irritant present in smog is [SSC(10+2) 2010]
     (a) nitric oxide
     (b) sulphur dioxide
     (c) peroxyacetyl nitrate
     (d) carbon dioxide
Ans: (b)
269. "Which one among the following is not a property of salt? [NDA 2010]
     (a) Salts have ordered packing arrangements called lattices
     (b) Salts have low melting points but high boiling points