151. Each day human body breathe in _______ liters of air.
(A) 5,000 to 10,000
(B) 10,000 to 15,000
(C) 15,000 to 20,000
(D) 20,000 to 25,000

152. The most abundant element in the universe is
(A) Hydrogen
(B) Oxygen
(C) Carbon dioxide
(D) Silicon

153.  The substance which increases the rate of chemical reaction is
(A) Metal
(B) Catalyst
(C) Alloy
(D) Enzymes

154.  The average human body contains about _______ gram of Sodium Chloride.
(A) 190
(B) 210
(C) 230
(D) 250

(A) Power of Hydrogen
(B) Possibility of Hydrogen
(C) Population of Hydrogen
(D) Position of Hydrogen

156. The best soil pH value for most crops and plants is
(A) 4.5
(B) 5.5
(C) 6.5
(D) 7.5

157.  __________ are biological catalysts.
(A) Enzymes
(B) Minerals
(C) Proteins
(D) Vitamins

158.  The most abundant constituent in Air is
(A) Oxygen
(B) Hydrogen
(C) Carbondioxide
(D) Nitrogen

159. Isotopes are atoms of the same element with different numbers of
(A) Protons
(B) Electrons
(C) Neutrons
(D) Positron

160. Over __________ of the elements in the Periodic Table are Metals.
(A) 60%
(B) 65%
(C) 70%
(D) 75%