Which one of the following is used as preservative?
Sodium benzoate
Ammonium sulphate
Sodium chloride
Copper sulphate
Which one of the following is a step of analogy strategy in science?
Presentation of abstraction
Interlinking concepts
Application
Map similarities
If the frequency of a simple pendulum is 2 Hz, how many oscillations will it complete in 16s?
16
64
32
8
Which one of the following metals burns, if kept in air?
Magnesium
Aluminum
Zinc
Sodium
D.
Sodium
Sodium is stored under kerosene oil to prevent their reaction with the oxygen, moisture and carbon dioxide of air. They are so reactive that they react vigorously with oxygen. They catch fire and start burning when kept open in the air.
Magnesium hydroxide (Mg (OH)2) is used as
reducing agent
anti-acid
fermentation agent
oxidising agent
Which one of the following gases burn with pop sound?
Hydrogen
Nitrogen dioxide
Sulphur dioxide
Oxygen
Which of the following is/are example(s)of non-contact force?
Muscular force
Gravitation force
Magnetic force
Both (A) and (B)