Atomic Structure

Total Questions: 39

1. Who is regarded as the Father of Modern Chemistry? [65th B.P.S.C. (Pre) 2019]

(a) Rutherford
(b) Einstein
(c) Lavoisier
(d) C.V. Raman
(e) None of the above/More than one of the above

Correct Answer: (c) Lavoisier
Note:

French nobleman and chemist Antoine Lavoisier is regarded as the 'Father of Modern Chemistry'. Lavoisier is most noted for his discovery of the role oxygen plays in combustion. He recognized and named oxygen (1778) and hydrogen (1783), wrote the first extensive list of elements and helped to reform chemical nomenclature.

2. The positively charged part at the centre of an atom is called as: [63rd B.P.S.C. (Pre) 2017]

(a) Proton
(b) Neutron
(c) Electron
(d) Nucleus
(e) None of the above/More than one of the above

Correct Answer: (d) Nucleus
Note:

The positively charged part at the centre of an atom is called as nucleus. The atomic nucleus is the small, dense region consisting of proton and neutron at the centre of an atom.

3. Constituents of atomic nucleus are – [U.P. P.C.S. (Pre) 1996, 41st B.P.S.C. (Pre) 1996, 43rd B.P.S.C. (Pre) 1999]

(a) Electron and proton
(b) Electron and neutron
(c) Proton and neutron
(d) Proton, neutron and electron

Correct Answer: (c) Proton and neutron
Note:

The constituents of an atom are protons, neutrons and electrons. The protons and neutrons (nucleons) are found in the nucleus of atoms. The nucleus of an atom is surrounded by electrons.

4. The nucleus of an atom consists of: [67th B.P.S.C. (Pre) (Re. Exam) 2022]

(a) electrons and neutrons
(b) electrons and protons
(c) protons and neutrons
(d) electrons only
(e) None of the above/More than one of the above

Correct Answer: (c) protons and neutrons
Note:

The constituents of an atom are protons, neutrons and electrons. The protons and neutrons (nucleons) are found in the nucleus of atoms. The nucleus of an atom is surrounded by electrons.

5. Which among the following is an incorrect option? [67th B.P.S.C. (Pre) 2022]

(a) Atom is electrically neutral due to the presence of protons and electrons inside the nucleus.
(b) Electrons are negatively charged and have negligible mass.
(c) Atomic number is the number of protons in an atom of an element.
(d) Isotopes are useful as nuclear fuel, in medical field; in carbon dating, etc.
(e) None of the above/More than one of the above

Correct Answer: (a) Atom is electrically neutral due to the presence of protons and electrons inside the nucleus.
Note:

An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons. The atomic nucleus consists of protons and neutrons while electrons revolve around the nucleus. The positive charges in an atom equal the negative charges, so the atom has no overall charge; it is electrically neutral. Statements of options (b), (c), and (d) are correct.

6. Which of the following statement about molecular structure is correct: [R.A.S./R.T.S. (Pre) 1992]

(a) Neutron and electron are found inside the nucleus and protons revolve around the nucleus.
(b) Electron and proton are inside the nucleus and neutron revolve around the nucleus.
(c) Proton and neutron are inside the nucleus and electrons revolve around the nucleus.
(d) Proton, neutron and electron all are inside the nucleus.

Correct Answer: (c) Proton and neutron are inside the nucleus and electrons revolve around the nucleus.
Note:

7. Which of the following is not a part of an atom? [M.P.P.C.S. (Pre) 2005]

(a) Electron
(d) Photon
(b) Proton
(d) Photon

Correct Answer: (d) Photon
Note:

Proton, electron and neutron are part of an atom, but the photon is associated with light energy and also known as the energy packet of light.

8. A single type of atom is found in – [53rd to 55th B.P.S.C. (Pre) 2011]

(a) Compounds of minerals
(b) Mixture of minerals
(c) Native elements
(d) None of the above

Correct Answer: (c) Native elements
Note:

Native element is a material that consists of a single type of atom, while a compound consists of two or more types of atoms.

9. The atomic nucleus was discovered by: [R.A.S./R.T.S. (Pre) 2003]

(a) Rutherford
(b) Dalton
(c) Einstein
(d) Thompson

Correct Answer: (a) Rutherford
Note:

The nucleus is a very dense region consisting of protons and neutrons at the centre of an atom. It was discovered in 1911 as a result of Ernest Rutherford’s interpretation of the 1909 Geiger–Marsden gold foil experiment. The proton-neutron model of the nucleus was proposed by Dmitri Ivanenko in 1932.

10. Consider the following events, and arrange them in correct chronological order starting from the earliest to the last activity: [U.P. R.O./A.R.O. (Pre) 2023]

(I) Discovery of pi meson
(II) Discovery of neutron
(III) Discovery of electron
(IV) Discovery of proton

Select the correct answer from the code given below:
Code:

(a) (III), (II), (IV), (I)
(b) (III), (IV), (II), (I)
(c) (I), (III), (IV), (II)
(d) (III), (IV), (I), (II)
(e) (IV), (III), (II), (I)

Correct Answer: (e) (IV), (III), (II), (I)
Note:

I) Discovery of pi meson – 1947 (by Cecil Powell)
II) Discovery of neutron – 1932 (by James Chadwick)
III) Discovery of electron – 1897 (by J.J. Thomson)
IV) Discovery of proton – 1886 (by Goldstein)

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