Chemistry - Atomic Structure
Exam Duration: 60 Mins Total Questions : 30
Which of the following is a correct statement about proton?
- (a)
It is nucleus of deuterium
- (b)
It is an ionised hydrogen atom
- (c)
It is an ionised hydrogen molecule
- (d)
It is a particle
The discovery of neutron became very late because
- (a)
it is present in nucleus
- (b)
it is a fundamental particle
- (c)
it does not move
- (d)
it does not carry any charge
The absolute value of charge on electron was determined by
- (a)
JJ Thomson
- (b)
Rutherford
- (c)
Priestly
- (d)
RA Millikan
Match the Column I with Column II.
Column I | Column II |
A. Proton | 1. Rutherford |
B. Electron | 2. Chadwick |
C. Neutron | 3. Thomson |
D. Nucleus | 4. Goldstein |
- (a)
A B C D 4 3 2 1 - (b)
A B C D 3 2 1 4 - (c)
A B C D 2 1 4 3 - (d)
A B C D 1 4 3 2
Match the column I and Column II and select the correct answer using the codes given below the columns.
Column I (Characteristic) |
Column II (Particle) |
A. Zero mass | 1. Positron |
B. Fractional charge | 2. Neutrino |
C. Fractioal spin | 3. Quark |
D. Integral spin | 4. Photon |
- (a)
A B C D 2 3 1 4 - (b)
A B C D 3 2 4 1 - (c)
A B C D 2 3 4 1 - (d)
A B C D 3 2 1 4
Consider the following statements in respect of hydrogen atom
It can attain the stability
1. by losing an electron
2. by gaining an electron
3. by forming an electron pair with other atom
Which of the statements given above are correct?
- (a)
1 and 3 only
- (b)
1 and 2 only
- (c)
2 and 3 only
- (d)
1,2 and 3
Two atoms are said to be isotopes if
- (a)
they have the same atomic number, but different mass number
- (b)
they have the same number of neutrons, but different mass number
- (c)
the sum of the number of protons and neutrons is the same but the number of protons is different
- (d)
they have the same number of neutrons, but different modes of radoactive decay
Which of the recent developments has proved the existence of atoms?
- (a)
Scanning tunneling microscopy
- (b)
X-ray diffraction
- (c)
Infrared spetroscopy
- (d)
Mass spectroscopy
In an atomic nucleus, neutrons and protons are held together with each other?
- (a)
gravitational forces
- (b)
magnetic forces
- (c)
exchange forces
- (d)
coulombic forces
The number of water molecules differing in molecular mass formed by hydrogen isotopes 1H, 2H, 3H and oxygen isotopes 16O, 17O, 18O is
- (a)
6
- (b)
9
- (c)
12
- (d)
18
Which one of the following element has two electrons in the K-shell only?
- (a)
Hydrogen
- (b)
Helium
- (c)
Neon
- (d)
Sulphur
In an atom, the order of filling up of the orbitals is governed by
- (a)
Aufbau's principal
- (b)
Heisenberg's uncertainty principle
- (c)
Hund's rule
- (d)
Pauli's exclusion principle
Which one of the following statements is correct?
- (a)
Only electrons reside the nucleus of an atom
- (b)
Both electrons and protons reside inside the nucleus of an atom
- (c)
Only neutrons reside inside the nucleus of an atom
- (d)
Both protons and neutrons can reside inside the nucleus of an atom
Regarding the atom of a chemical element, the magnetic quantum number refers to
- (a)
orientation
- (b)
shape
- (c)
size
- (d)
spin
Match the Column I (Discovery) with Column II (Scientist) and select the correct answer using the codes given below thw columns.
Column I (Discovery) |
Column II (Scientist) |
A. Radioactivity | 1. Moseley |
B. Quantum theory | 2. Planck |
C. Theory of photoelectric effect | 3. Becquerel |
D. Atomic number | 4. Einstein |
5. Rutherford |
- (a)
A B C D 3 2 4 1 - (b)
A B C D 4 5 3 2 - (c)
A B C D 3 5 4 2 - (d)
A B C D 4 2 3 1
Rutherford's model of atom is considered unsuitable because
- (a)
a positively charged nucleus remain separated from negatively charged electrons
- (b)
an accelerated electron would continuously lose energy in the form of radiation
- (c)
nuclear mass is not sufficiently heavy to keep the light electron in its orbit
- (d)
the center of gravity of the system would be with in the volume of the nucleus
Assertion (A) Electrons are negatively charged.
Reason (R) The application of electric and magnetic field deflected the rays in the discharge tube towards the cathode.
- (a)
Both A and R are individually true and R is the correct explanation of A
- (b)
Both A and R are individually true nut R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
Which one among the following statements about an atom is not correct?
- (a)
Atoms always combine to form molecule
- (b)
Atoms are the basic units from which molecules and ions are formed
- (c)
Atoms are always neutral in nature
- (d)
Atoms aggregate in large number to form the matter we can see, feel and touch
Which of the following statements does not form a part of Bohr's model hydrogen atom?
- (a)
Energy of the electrons in the orbit is quantised
- (b)
The electron in the orbit nearest the nucleus has the lowest energy
- (c)
Electrons revolve in different orbits around the nucleus
- (d)
The position and velocity of the electrons in the orbital cannot be determined simultaneously
Which one among the following transitions of electron of hydrogen atom emits radiation of the shortest wavelength?
- (a)
n=2 to n=1
- (b)
n=3 to n=2
- (c)
n=4 to n=3
- (d)
n=5 to n=4
In an X-ray tube, a potential difference of several thousand volts accelerates electrons which then hit the target and X-rays are emitted. Why are the X-rays emitted?
- (a)
Because of electron transition in an atom
- (b)
Because of removal of an electron from an atom
- (c)
Because electron get decelerated
- (d)
Because of the heat prodacuced in the collision
A body is charged negatively, It implies that
- (a)
it has lost some of its protons
- (b)
it has lost some of its electrons
- (c)
it has gained electrons from outside
- (d)
None of the above
Which one of the following is the correct configuration for Fe3+ (Z=26)?
- (a)
[Ar] 4s2 3d6
- (b)
[Ar] 4s2 3d3
- (c)
[Ar] 3d5
- (d)
[Ar] 4s2 3d4
Match the principle in Column I with discoverer in Column II.
Column I (Principle) |
Column II (Discoverer) |
A. Exclusion principal | 1. Hund |
B. Multiplicity rule | 2. Heisenberg |
C. Uncertainty principle | 3. Planck |
D. Quantum theory | 4. Pauli |
Select the correct answer using the codes given below the columns.
- (a)
A B C D 2 3 4 1 - (b)
A B C D 3 4 1 2 - (c)
A B C D 4 1 2 3 - (d)
A B C D 1 2 4 3
The atomic weights are expressed in terms of atomic mass unit. Which one of the following is used as a standard?
- (a)
1H1
- (b)
12C6
- (c)
16O8
- (d)
35C17
Which involves the emission of least energy in the hydrogen atom?
- (a)
An electron moving from n=4 to n=2
- (b)
An electron moving from n=3 to n=2
- (c)
An electron moving from n=4 to n=1
- (d)
An electron moving from n=5 to n=2
Consider the following
1. The energy of the electrons in the orbit is quantised.
2. Electrons revole only in those orbits for which angular momentum is an integral multiple of h/2l.
3. The electrons revolve in different orbits around the nucleus.
4. The electrons emit energy during revolution due to the presence of Coulombic forces of attraction.
Which of the above is/are false about Bohr's model of atom?
- (a)
Only 1
- (b)
1 and 4
- (c)
Only 4
- (d)
2 and 3
Propagation of light quanta may be described by
- (a)
Photons
- (b)
Protons
- (c)
Neutrons
- (d)
Electrons
Consider the following statements
1. JJ Thomson proposed that electrons are embedded in a positive sphere.
2. Rutherford's model of the atom proposed that a very tiny nucleus is present inside the atom and electrons revolve around this nucleus.
3. Neils Bohr's model proposed that electrons are distributed in different shells with discrete energy around the nucleus. If the atomic shells are complete, then the atom will be stable and less reactive.
Which of the statements given above are correct?
- (a)
1 and 2
- (b)
2 and 3
- (c)
1 and 3
- (d)
1,2 and 3
The triad of nuclei which is isotonic is
- (a)
6C14 , 7N15 , 9F17
- (b)
6 C 12 , 7 N 14 , 9F19
- (c)
6 C 14 , 7 N 14 , 9F17
- (d)
6 C 14 , 7 N 14 , 9F19