Railway Science (Chemistry-Discoveries)

Total Questions: 20

1. Who provided the basic theory about the nature of matter ? [RRB NTPC CBT - I (13/01/2021) Morning]

Correct Answer: (b) John Dalton
Solution:

Gregor Mendel discovered the basic principles of heredity through experiments in his garden (pea). Antoine-Laurent de ‘Lavoisier’: “Father of modern chemistry”.
John Milton: He was an English poet, polemicist, a scholarly man of letters, and a civil servant for the Commonwealth of England under Oliver Cromwell.

2. Name the British Chemist who presented the atomic theory in 1808, on conservation of mass and law of definite proportions, which was a turning point in the study of motion. [RRB NTPC CBT - I (20/01/2021) Evening]

Correct Answer: (a) John Dalton
Solution:

John Dalton: Law of Conservation of Mass - Mass is neither created nor destroyed in chemical reactions.
Law of definite proportions - Every chemical compound contains fixed and constant proportions (by mass) of its constituent elements. According to Dalton’s atomic theory - All matter is composed of small particles called atoms.
Ernest Rutherford: Nuclear structure of the atom, discovered alpha and beta rays and proposed the laws of radioactive decay. Antoine Lavoisier: “Father of modern chemistry”.

3. Name the German Chemist who grouped elements into triads in 1817 ? [RRB NTPC CBT - I (20/01/2021) Evening]

Correct Answer: (c) Johann Wolfganag Dobereiner
Solution:

Dmitri Ivanovich Mendeleev - Periodic classification of the chemical elements (arranged in order of increasing atomic weight). John Newlands (1863.) - Every eight elements had similar properties and called this the law of octaves. Henry Moseley (1913) - Systematic relation between wavelength and atomic number.

4. Scottish physician Daniel Rutherford discovered ______ in 1772. [RRB ALP Tier - II (21/01/2019) Afternoon]

Correct Answer: (c) Nitrogen
Solution:

Nitrogen (N): Constitutes 78% of Earth's atmosphere. Block - p-block, Group - 15, Atomic number - 7. Other gases and their discoverer: Oxygen (O) - Joseph Priestly. Hydrogen (H) - Henry Cavendish. Chlorine (Cl) - Carl Wilhem Scheele. Helium (He) - Frankland and Lockyer.

5. Henry Cabendish discovered ______ in 1766 ? [RRB ALP Tier - II (23/01/2019) Afternoon]

Correct Answer: (d) Hydrogen
Solution:

Oxygen (O) - It was discovered by Swedish chemist, Carl William Scheele (1772). Helium (He) - The first evidence of helium was obtained on August 18th, 1868 by French astronomer Jules Janssen.
Periodic Table - It was discovered by Dmitri Mendeleev In 1869. The periodic table of chemical elements organizes all discovered chemical elements in rows and columns according to increasing atomic number.

6. Which of these scientists discovered the radioactive element radium ? [RRB ALP Tier - II (08/02/2019) Morning]

Correct Answer: (b) Marie Curie
Solution:

Marie Curie - Discovered polonium and radium. Awards : Nobel Prize in Physics (1903), Nobel Prize in Chemistry (1911).
Amedeo Avogadro (Italian mathematical physicist) - Avogadro’s law that, under controlled conditions of temperature and pressure, equal volumes of gasses contain an equal number of molecules.
Louis Pasteur (French chemist and microbiologist) - Discoveries of the principles of vaccination, microbial fermentation, and pasteurization.
Leonard Euler (Swiss mathematician) - mathematics and physics including analytic geometry, trigonometry, geometry, calculus and number theory.

7. The law of definite proportions was stated by______. [RRB Group D 28/09/2018 (Morning)]

Correct Answer: (c) Proust
Solution:

Proust : The law of definite proportions states that a given chemical compound always contains the same elements in the exact same proportions by mass. Scientists and their discoveries : Democritus - Coined the word ‘Atom’, Lavoisier - Mass conservation theory, John Dalton - Atomic theory.

8. Which of the following scientists suggested that symbols of elements can be formed from one or two letters of the name of the element? [RRB Group D 01/10/2018 (Morning)]

Correct Answer: (a) Berzelius
Solution:

He discovered the chemical elements cerium (Ce) and selenium (Se), and technique of isolating silicon (Si) and thorium (Th).

9. Who discovered the theory of nuclear forces? [RRB Group D 04/10/2018 (Morning)]

Correct Answer: (a) Hideki Huaka
Solution:

Nuclear forces - The forces acting between 2 or more nucleons are known as Nuclear forces. S.N. Bose is known for developing Bose-Einstein Condensate. J.C. Bose invented the crescograph. J.J. Thomson is known to have discovered electrons.

10. ____ made the first observations on platinum as a catalyst. [RRB Group D 12/10/2018 (Evening)]

Correct Answer: (c) Dobereiner
Solution:

Johann Wolfgang Dobereiner made the first observations on platinum as a catalyst in 1823. He noted that a sponge of platinum could ignite a mixture of hydrogen and air at room temperature, highlighting its catalytic properties.