Science Class 7th
221. In screening process of water treatment plant natural contaminates such as plant, woods etc. are removed.
A) Small
B) Middle
C) Large
D) None of these
222.In coagulation and flocculation process of water treatment plant the removal of_______ particles from water take place.
A) Micro
B) Small
C) Suspended
D) None of these
223. Floc settles to the bottom of the tank containing water due to its weight, this process is called
A) Condensation
B) Boiling
C) Sedimentation
D) None of these
224. Water is used for cleaning, washing, drinking, this is the use of water for purpose.
A) Industrial
B) Agricultural
C) Domestic
D) None of these
225. Water is used as coolant, ingredient, reagent etc, this is the use of water for purpose.
A) Domestic
B) Agricultural
C) Industrial
D) Transportation
226. Water is used for farming, gardening etc. This is the use of water for purpose.
A) Communities
B) Recreational
C) Agricultural
D) None of these
227. Harmful bacteria are removed from drinking water by passing :
A) Oxygen gas
B) Nitrogen gas
C) Chlorine gas
D) Carbon dioxide gas
228. Suspended particle from the drinking water are removed by :
A) Table salt
B) Chlorine
C) Charcoal
D) Potash alum
229. Distillation is a technique of :
A) Separation
B) Preparation
C) Filtration
D) Disinfection
230. has mass and occupy space.
A) Water
B) Wood
C) Matter
D) Air
231. are the basic building blocks of matter.
A) Molecule
B) Atoms
C) Ions
D) Chemicals
232. The idea that all matter is made up of atoms was proposed by
A) Rutherford
B) Democritus
C) John Walton
D) None of the above
233. The word atom is derived from the greek word
A) Atomic
B) Atomics
C) Atomos
D) None of these
234. Atoms are composed of types of articles.
A) Four
B) Three
C) Two
D) None of these
235. Electron, protons are basic particles of atom.
A) Protonious
B) Electolysis
C) Neutron
D) None of these
236. Most of the atomic mass is comprised of
A) Proton, electron
B) Electron ,neutron
C) Neutron , proton
D) None of these
237. ______ reside in the nucleus.
A) Electron, proton
B) Neutron , proton
C) Neutron, electron
D) None of these
238. Protons have charge
A) Positive
B) Negative
C) Neutral
D) None of these
239. Neutrons have charge
A) Positive
B) Negative
C) No
D) None of these
240. Electrons have charge.
A) Negative
B) Positive
C) No
D) None of these