General Science - Study Mode

[#71] From which mineral is radium obtained?
Correct Answer

(D) Pitchblende

Explanation

Solution: On April 20, 1902, Marie and Pierre Curie successfully isolate radioactive radium salts from the mineral pitchblende in their laboratory in Paris. In 1898, the Curies discovered the existence of the elements radium and polonium in their research of pitch blende.

[#72] What is laughing gas?
Correct Answer

(A) Nitrous Oxide

Explanation

Solution: Nitrous oxide, commonly known as laughing gas or nitrous, is a chemical compound, an oxide of nitrogen with the formula N 2 O.

[#73] Actinides are the elements with atomic numbers from
Correct Answer

(C) 89 to 103

Explanation

Solution: Actinides are the elements with atomic numbers from 89 to 103.

[#74] The two elements that are frequently used for making transistors are:
Correct Answer

(B) Silicon and Germanium

Explanation

Solution: The two elements that are frequently used for making transistors are Silicon and Germanium.

[#75] The filament of an electric bulb is made of
Correct Answer

(A) Tungsten

Explanation

Solution: The filament of an electric bulb is made of Tungsten.