TRB Model Question Papers with Answer in Chemistry - 5

Question: 21

Bleaching powder is manufactured by using

(A) Solvay tower

(B) Bachmann’s plant

(C) Contact chamber

(D) Rotator kiln

Question: 22

Which gas is used in filling electric bulbs?

(A) Argon

(B) Neon

(C) Radon

(D) Krypton

Question: 23

The phenomenon of radioactivity was discovered by

(A) Marie Curie

(B) Pierre Curie

(C) J.J. Thomson

(D) Henri Becquerel

Question: 24

Which one of the following elements exists in liquid state at room temperature?

(A) Calcium

(B) Mercury

(C) Sodium

(D) Lead

Question: 25

When one substance is oxidised, another element is

(A) Neutralised

(B) Decomposed

(C) Replaced

(D) Reduced