191. Elements which have same number of protons but different number of neutrons are called as _________ ?
A. Isotopes
B. Isomers
C. Allotropes
D. Allomers

192. Hydrogen bomb is based on the principle of ________ ?
A. Nuclear fusion
B. Artificial radioactivity
C. Natural radioactivity
D. Nuclear fission

193. Brass gets discoloured in air because of the presence of which of the following gases in air ________ ?
A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Hydrogen sulphide

194. A ‘breath test’ used by traffic police to check drunken driving uses ____?
A. Turmeric on filter paper
B. Silica gel coated with silver nitrate
C. potassium permanganate-sulphuric acid
D. Potassium dichromatic-sulphuric acid

195. What is the chemical formula for Sodium carbonate _______ ?
A. Na3CO2
B. CNa2O3
C. Na2CO3
D. Na3CO3

196. A mixture of sand and naphthalene can be separated by ________ ?
A. Chromatography
B. Fractional distillation
C. Sublimation
D. None of these

197. The M.K.S. system was first introduced by _________ ?
A. Giorgi
B. Archimedes
C. Eienstein
D. Newton

198. What is the chemical formula for Sulfuric acid?
A. C2H6O
B. CaSO4
C. C2H4O2
D. H2SO4

199. Which of the following is a diverse group of hydrophobic molecules?
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic acids

200. What is the Molecular Formula for Glucose _______ ?
A. C4H10O6
B. C5H11O6
C. C6H12O6
D. S6H12O6