1. In 1903 who had proposed the model of an atom, due to which electrons and protons were known to us ?
A. Dalton
B. J J Thomoson
C. Rutherford
D. Goldstein
ANSWER:B.J J Thomoson
SOLUTION : J J Thomoson
2. Which model of an atom is similar to a Christmas pudding ?
A. Thomson’s model
B. Rutherford model
C. Dalton’s model
D. None of the above
ANSWER:A.Thomson’s model
SOLUTION:Thomson proposed the model of an atom to be similar to that of a Christmas pudding. The electrons, in a sphere of positive charge, were like currants (dry fruits) in a spherical Christmas pudding. Q. The plum pudding model was proposed by J.J Thomson.
3. The present concept of the structure of an atom is given by which scientist ?
A. Rutherford
B. Goldstein
C. Niels Bohr
D. J J Thomson
ANSWER : C.Niels Bohr
SOLUTION: Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research
4. How many electrons does the outermost shell of neon have?
A. 4
B. 8
C. 2
D. 16
ANSWER:B.8
SOLUTION:Neon has eight electrons in its outermost shell. This shell is considered complete, or filled, and is known as the 2n shell. Because of this, neon is a noble gas that exists as single atoms and doesn’t form chemical compounds.
5. The orbit / shell closest to the nucleus is called __________ shell.
A. P
B. L
C. K
D. M
ANSWER:C.K
SOLUTION:The shell closest to the nucleus of an atom is called the K shell, also known as the 1 shell. The next shells are the L shell, or 2 shell, and the M shell, or 3 shell, and so on, moving farther away from the nucleus.
6. The L – Shell holds maximum _________electrons.
A. 4
B. 2
C. 6
D. 8
ANSWER:D.8
SOLUTION:The L-shell, or second shell, of an atom can hold up to eight electrons.
7. The copper atom consists of _______ electrons in the outermost shell.
A. 2
B. 4
C. 3
D. 1
ANSWER:D.1
SOLUTION :
This configuration indicates that copper has 29 electrons distributed in its electron shells. The first shell has 2 electrons, the second shell has 8 electrons, the third shell has 18 electrons, and the fourth shell has 1 electron. The outermost shell of copper is the fourth shell with 1 electron in the 4s orbital.
8. Name an atom in which the nucleus of that atom does not contain any neutrons?
A. Oxygen
B. Hydrogen
C. Phosphorous
D. Sodium
ANSWER: B.Hydrogen
SOLUTION: Hydrogen (H) is the only atom that doesn’t have neutrons in its nucleus. The first isotope of hydrogen, called protium (1H1), is the only stable atom that doesn’t have neutrons. Protium is the simplest atom, containing only one proton and one electron.
9. Which model does not able to explain the stability of an atom?
A. Bohr’s Model
B. Rutherford’s Model
C. Thomson’s Model
D. None of the above
ANSWER:B.Rutherford’s Model
SOLUTION: Rutherford’s model could not explain this phenomenon because if a charged particle is in motion, it radiates energy which can cause it to collapse to the nucleus making it unstable. Rutherford’s model could not explain the stability of the atom.
10. In 1932 who had discovered neutron?
A. J J Thomson
B. James Chadwick
C. Goldstein
D. Rutherford
ANSWER: B. James Chadwick
SOLUTION:
The story begins in 1932, with the discovery of the neutron by Sir James Chadwick, an English physicist. Until 1932, the atom was known to consist of a positively charged nucleus surrounded by enough negatively charged electrons to make the atom electrically neutral.