291. The heaviest naturally-occurring element is_________?
A. Radium
B. Platinum
C. Uranium
D. Cadmium
292. The heaviest man made element found so for is__________?
A. Promethium
B. Ununoctium
C. Francium
D. Technetium
293. Which instrument is used for viewing the sun?
A. Stroboscope
B. Heliograph
C. Solograph
D. None of these
294. ___________ is a strong smelling agent added to LPG cylinders to detect leakage?
A. Nitrogen Peroxide
B. Ethyl Mercaptan
C. Carbon Monoxide
D. Sulphur Dioxide
295. A crescograph is a device for measuring the growth in __________?
A. Micro Organism
B. Plants
C. Human
D. Pollution
296. Which of the following is used in water purification?
A. Reverse Osmosis
B. Osmosis
C. Cytolysis
D. Turgor Pressure
297. lightest metal is__________?
A. Lithium
B. Sodium
C. Magnesium
D. Aluminium
298. Which of the following pollutants in water causes “Minamata disease?
A. Methyl Mercury
B. Lead
C. Salmonella
D. Perchlorate
299. The process of converting wet waste to manure is___________?
A. Metabolism
B. Conservation
C. Incineration
D. Composting
300. Which of the following organisms releases molecular oxygen into water?
A. E.coli
B. Phytoplankton
C. Amoeba
D. Salmonella