IISER Chemistry - Atomic Structure and Periodic Properties of Elements
Exam Duration: 45 Mins Total Questions : 30
The line spectra are the characteristics of
- (a)
atoms in the excited state
- (b)
atoms in ground state
- (c)
molecules in the excited state
- (d)
molecules in ground state
The radius of Bohr's first for hydrogen atom would be
- (a)
0.50X10-10 m
- (b)
0.43X10-10 m
- (c)
0.53X10-10 m
- (d)
0.63X10-10 m
Which one of the following is isoelectronic with CO?
- (a)
O2-
- (b)
O3
- (c)
NO
- (d)
\(C\overline { N } \)
The maximum number of electrons in f-orbitals is
- (a)
two
- (b)
ten
- (c)
six
- (d)
fourteen
The splitting of the spectral lines under the influence of an electric field is called
- (a)
Raman effect
- (b)
Zeeman effect
- (c)
Stark effect
- (d)
Photoelectric effect
Which one of the following species possesses maximum size?
- (a)
Na+
- (b)
F-
- (c)
Ne
- (d)
O2-
What will be de Broglie wavelength of an electron moving with a velocity of \(1.20\times {10}^{5} m{s}^{-1}\)?
- (a)
6.068X10-9
- (b)
3.133X10-37
- (c)
6.626X10-9
- (d)
6.018X10-7
Helium atom is two times heavier than hydrogen molecule at 298 K. the average kinetic energy of helium is
- (a)
same as that of hydrogen molecule
- (b)
two times that of hydrogen molecule
- (c)
half that of hydrogen molecule
- (d)
four times that of hydrogen molecule
The quantum numbers for 3d8 electrons would be
- (a)
n=3, l=2, m=+1, s=-1/2
- (b)
n=3, l=2, m=+2, s=-1/2
- (c)
n=3, l=1, m=+1, s=-1/2
- (d)
n=3, l=1, m=-1, s=-1/2
The designation of the orbital with n=3 and l=2 is
- (a)
15s
- (b)
5d
- (c)
3d
- (d)
4d
For a d-electron, the orbit angular momentum is
- (a)
\(\sqrt {6} h\)
- (b)
\(\sqrt {2} h\)
- (c)
\(h\)
- (d)
\(2\)
The quantum number which determines the shape of the orbital is
- (a)
principal
- (b)
azimuthal
- (c)
magnetic
- (d)
spin
Which of the following electronic configuration is not possible?
- (a)
1s2, 2s2, 2p6
- (b)
1s2, 2s2, 2p7
- (c)
1s2, 2s2
- (d)
1s2, 2s2, 2p5
The energy of the orbital in H atom is given by the relation E=-\(\frac {constant}{ {n}^ {2}}\)k J mol-1 which of the following properties represents the constant in the above relation?
- (a)
Electron affinity
- (b)
Ionisation energy
- (c)
Electronegativity
- (d)
Bond energy
Electromagnetic radiation with maximum wave length is
- (a)
ultraviolet
- (b)
radiowave
- (c)
X-rays
- (d)
infrared
The ratio of energy of photon of \(\lambda\)=2000\(\mathring{A}\) to that of \(\lambda\)=4000\(\mathring{A}\) is:
- (a)
2
- (b)
1/4
- (c)
4
- (d)
1/2
Ruther ford's scattering experiment is related to the size of the
- (a)
Nucleus
- (b)
atom
- (c)
electron
- (d)
neutron
which of the following orbitals is cylindrically symmetrical about x-axis?
- (a)
pz -orbital
- (b)
py-orbital
- (c)
px-orbital
- (d)
dxz orbital
The ionic radii of N3-,O2-,F-,Na+ follows the order
- (a)
N3- > O2- > F- > Na+
- (b)
N3- > Na+ > O2- > F-
- (c)
Na+ > O2-> N3- > F-
- (d)
O2- > F- > Na+ > N3-
Among the following the element with highest ionisation potential is?
- (a)
boron
- (b)
carbon
- (c)
oxygen
- (d)
nitrogen
The element whose electronic configuration is 1s2 2s22p63s2 is:
- (a)
Metal
- (b)
Metalloid
- (c)
Inert gas
- (d)
Non-metal
Which of the following element has the highest electron affinity?
- (a)
Na
- (b)
K
- (c)
CI
- (d)
F
Ionisation potential of K would numberically be same as
- (a)
Electron affinity of K+
- (b)
electronegativity of K+
- (c)
ionisation potential of Na
- (d)
None of the above
Which set of elements have strongest tendency to form anions?
- (a)
Na,CI,AI
- (b)
Cu,Ag,Au
- (c)
Be,F,N
- (d)
F,CI,Br
Which of the following represents element in order of increasing atomic size
- (a)
I, Br, CI
- (b)
Na, Mg, C
- (c)
C< N< O
- (d)
Li,Na,K
The number of radial nodes for 3p-orbital is
- (a)
3
- (b)
4
- (c)
2
- (d)
1
The ground state energy is correctly ordered in
- (a)
1s < 2s < 2p < 3d < 4s
- (b)
1s < 2s < 2p < 3s < 3p
- (c)
1s < 2s < 2p < 3s < 4s
- (d)
1s < 2s < 2p < 3p < 3s
What will the threshold frequency of metal, if binding energy of electron in a metal is 250 kJ mol-1 ?
- (a)
3.8 x 1038 s-1
- (b)
3.8 x 1035 s-1
- (c)
6.3 x 1011 s-1
- (d)
6.3 x 1014 s-1
Which of the following is responsible to rule out the existence of definite paths or trajectories of electrons?
- (a)
Pauli's exclusion principle
- (b)
Heisenberg's uncertainty principle
- (c)
Hund's rule of maximum multiplicity
- (d)
Aufbau principle
The ionisation enthalpy of hydrogen atom is 1.312 x 106 Jmol-1. The energy required to excite electron in atom from n = 1 to n = 2 is
- (a)
8.51 x 105 J mol-1
- (b)
6.56 x 105 J mol-1
- (c)
7.56 x 105 J mol-1
- (d)
9.84 x 105 J mol-1