MCQGeeks
0 : 0 : 1
CBSE
JEE
NTSE
NEET
English
UK Quiz
Quiz
Driving Test
Practice
Games
NEET
NEET Chemistry MCQ
Structure Of Atom Mcq Neet Chemistry
Quiz 3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Q.1
Number of nodes in a 4d-orbital is
0%
a) 0
0%
b) 1
0%
c)2
0%
d)3
Explanation
number of nodes in any orbital is given by (n-l-1)for 4d , n=4 and l=2 For a given orbital, there are two types of nodes i.e. 1) Angular nodes (also known as nodal planes) 2) Radial nodes (also known as nodal regions). The number of angular nodes = l The number of radial nodes = (n - l - 1) Total number of nodes = n - 1 Where: n = Principal quantum number l = Azimuthal quantum number ∴ 4-1 =3 Answer: (b)
Q.2
If m has seven values, the value of azimuthal quantum number should be
0%
a) 1
0%
b) 2
0%
c)3
0%
d)4
Explanation
m can takes the values (2l+1) thus for l=3 m=7 Answer:(c)
Q.3
Correct expression derived for the energy of an electron in the nth energy level of H-atom is
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
Answer: (d)
Q.4
Which of the following orbitals is not symmetrical about the z-axis?
0%
a)pz
0%
b) dz2
0%
c)s
0%
d)dxz
Explanation
Answer: (d)
Q.5
How many electrons in an atom can have n=3, l=2, m=-1?
0%
a) 2
0%
b) 6
0%
c)10
0%
d)1
Explanation
TWo because scan be ± 1/2Answer: (a)
Q.6
The magnetic quantum number for the valance electron of Caesium ( at no 55) is
0%
a) 3
0%
b) 0
0%
c)-3
0%
d)Any number between -3 to +3
Explanation
Vance shell 6s1 for which l=0 and hence m=0 Answer:(b)
Q.7
Which of the following statement is incorrect regarding probability of fining the electron in px orbital
0%
a) It is zero at the nucleus
0%
b) It is zero on the Z-axis
0%
c) It is same on all sides around the nucleus
0%
d) It is maximum on the two opposite sides of the nucleus along X-axis
Explanation
Answer: (c)
Q.8
Hund's rule deals with the distribution of electrons in
0%
a)a principal shell
0%
b) different subshells
0%
c)orbitals with slightly different energies
0%
d)degenerate orbitals
Explanation
Answer: (d)
Q.9
ThE number of nodes in the shape of ns-orbital is equal to
0%
a) n
0%
b) n+1
0%
c)n-1
0%
d)n2
Explanation
Answer: (c)
Q.10
f the value of azimuthal quantum number of an electron is 2, then which of the following value of magnetic quantum numbers is not permissible
0%
a) 0
0%
b) 2
0%
c)-2
0%
d)3
Explanation
m can take values from - l to +l Since l=2 thus m=-2, -1, 0, +1, +2 Answer:(d)
Q.11
The possible subshells in n=3 energy shell are
0%
a) s, p, d
0%
b) s, p, d, f
0%
c) s, p
0%
d) s only
Explanation
for n=3, l=0, 1, 2 ( s, p, d) Answer: (a)
Q.12
The d-orbital whose four lobes lie along the axis is
0%
a)dz2
0%
b) dxy
0%
c)dyz
0%
d)dx2-y2
Explanation
Answer: (d)
Q.13
If the quantum number for the 5th electron in carbon atoms are 2,1,1, +1/2 then for 6th electron, these values would be
0%
a) 2,1,0,-1/2
0%
b) 2,0,1,+1/2
0%
c)2,1,1,-1/2
0%
d)2,1,-1,+1/2
Explanation
5th electron of carbon is in 2px1, 6th electron is in 2py1 with spin in same directionAnswer: (d)
Q.14
he shape of the orbital with l=1 and m=0 is
0%
a) spherical
0%
b) dum-bell
0%
c)clover leaf
0%
d)dough nut
Explanation
Answer:(b)
Q.15
The correct set of quantum numbers for the unpaired electron of Cl atom is
0%
a) 2, 0, 0, +1/2
0%
b) 2, 1, -1, +1/2
0%
c) 3, 1, 1, ±1/2
0%
d) 3, 0, 0, ±1/2
Explanation
The unpaired electron of Cl atom is 3p1 for which n=3, l=1, m=-1,0 or +1 and s=±1/2 Answer: (c)
Q.16
in Aufbau principle, the word 'Aufbau'
0%
a)represents the name of scientist who developed the principle
0%
b) is a german word which means "building up"
0%
c)is related to the energy of electron
0%
d)is related to angular momentum of the electron
Explanation
Answer: (b)
Q.17
In an atomic orbital, the sign of lobes indicates the
0%
a) sign of the probability distribution
0%
b) sign of charge
0%
c)sign of wave function
0%
d)presence or absence of electron
Explanation
Answer: (c)
Q.18
Which shell would be the first to have g-subshell
0%
a) 4th
0%
b) 5th
0%
c)6th
0%
d)7th
Explanation
Answer:(b)
Q.19
The ( n+l) value of 3d energy level is
0%
a) 5
0%
b) 4
0%
c) 3
0%
d) 2
Explanation
for 3d, n=3 and l=2 Answer: (a)
Q.20
An orbit with l=0 is symmetric about the
0%
a)x-axis only
0%
b) y-axis only
0%
c)z-axis only
0%
d)nucleus
Explanation
l=0 then it is s orbital which is sphericalAnswer: (d)
Q.21
Which of the following orbital does not make sense?
0%
a) 3d
0%
b) 3f
0%
c)5p
0%
d)7s
Explanation
if n=3 then values of l=1, 2, 3 thus 3d is possibleAnswer: (b)
Q.22
or given principal level n=4 the energies of its sub-shells are in the order
0%
a) s
0%
b)s
0%
c)d
0%
d)s
Explanation
Answer:(b)
Q.23
Which of the following orbital does not exists
0%
a) dx2- y2
0%
b) dx2- z2
0%
c) dxz
0%
d) dxy
Explanation
Answer: (b)
Q.24
In which of the following electron distribution in ground state, only Hund's rule is violated
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
2p orbitals should have one electron eachAnswer: (c)
Q.25
Which of the following orbitals has appearance like a baby soother?
0%
a) dxy
0%
b) dyz
0%
c)dx2-y2
0%
d)dz2
Explanation
Shape of dz2Answer: (d)
Q.26
How many electrons can have n=4 and l=2
0%
a) 6
0%
b) 10
0%
c)18
0%
d)32
Explanation
n=4, l=2 , m=-2, -1, 0, +1, +2, there are five values of m and for each value of m there are two electrons off opposite spin thus total 10 electrons Answer:(b)
Q.27
In which of the following case, the degeneracy of orbitals does not exist?
0%
a) s-subshell
0%
b) p-subshell
0%
c) d-subshell
0%
d) f-subshell
Explanation
Degeneracy is meaning less for s-subshell because it have only one orbitAnswer: (a)
Q.28
Number of unpaired electrons in chromium ( Z=24) is
0%
a)4
0%
b) 3
0%
c)6
0%
d)5
Explanation
configuration of Cr is [Ar] 3d54s1 Thus number of unpaired electrons are 6Answer: (c)
Q.29
Which of the following statement is incorrect?
0%
a) Probabilities are found by solving Schrodinger wave equation
0%
b) Energy of the electron at infinite distance is zero and yet it is maximum
0%
c)Some spectral lines of an element may have the same wave number
0%
d)The position and momentum of a rolling ball can be measured accurately
Explanation
No two spectral line can have same wave number. If it is same then lines are sameAnswer: (c)
Q.30
iven the set of possible quantum numbers that describes the highest energy electron in neon when the atom is in its first excited state.
0%
a)n=2, l=1, l=-1, s=1/2
0%
b) n=3, l=1, l=-1, s=1/2
0%
c) n=3, l=0, l=0, s=1/2
0%
d)n=3, l=1, l=0, s=1/2
Explanation
[Ne]=1s2 2s2 2p6 After excitation EC=1s2 2s2 2p53s1 Answer:(c)
Q.31
Which of the following arrangement of electrons is most likely to be stable
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
option 'c' exactly half filled hence stable Answer: (c)
Q.32
Electronic configuration of hydride ion is
0%
a)1s1
0%
b) 1s1 2s1
0%
c)1s2
0%
d)1s0
Explanation
Hydride ion is H-1 thus number of electrons are 2Answer: (c)
Q.33
Which of the following statement relating to the spectrum of hydrogen atom is false
0%
a) the lines can be defined by quantum number
0%
b) the line of shortest wavelength in blamer series corresponds to n=3 and n=2 levels
0%
c)The spectral lines are closer together at long wavelengths
0%
d)A continuum occurs at n=∞
Explanation
Answer: (a)
Q.34
he number of unpaired electrons in Cu+ is (z=29)
0%
a)1
0%
b)2
0%
c)0
0%
d)3
Explanation
Total electron in Cu+ is 29-1=28 thus electron configuration is [Ar] 3d10 d is full no unpaired electron Answer:(c)
Q.35
Which of the following statement is correct?
0%
a) An orbital containing an electron having quantum numbers n=2, l=0, s=+1/2 is spherical
0%
b) All photons have same energy
0%
c) The frequency of X-rays is less than radio waves
0%
d) As intensity of light increases, the frequency increases
Explanation
Answer: (a)
Q.36
The set of quantum numbers for the 19th electron in chromium is
0%
a)n=4, l=0, m=0, s=+1/2 or -1/2
0%
b) n=3 , l=2, m=1, s=+1/2 or -1/2
0%
c)n=3, l=2, m=-1, s=+1/2 or -1/2
0%
d)n=4 , l=1, m=0, s=+1/2 or -1/2
Explanation
Configuration for 19th electron will be 1s2 2s2 2p6 3s23p64s1 ( 19th electron). n=4, l=0, m=0, s=+1/2 or -1/2 Answer: (a)
Q.37
Which of the following species is diamagnetic
0%
a) Ti2+ ( Z=22)
0%
b)Zn1+ (Z=30)
0%
c)Ni1+ (Z=28)
0%
d)Cr3+ (Z=24)
Explanation
Species will be dimagnetic if all electrons are pairedin Ti2+=[Ar]3d2 all electrons are pairedAnswer: (a)
Q.38
hich out of following configuration is incorrect
0%
a) 1s2, 2s2, 2px2, 2py2,2pz0
0%
b)1s2, 2s2, 2px2, 2py1
0%
c)1s2, 2s2, 2px1, 2px1,2py1, 2pz1
0%
d)1s2, 2s2,2p6,3s2, 3p6, 3d5, 4s1
Explanation
Option "a" violates Hund's rule which states that: Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. is incorrect configuration Answer:(a)
Q.39
A mass spectrograph is an instrument which is capable of differentiating and identifying particles
0%
a) of different masses
0%
b) of different charges
0%
c) of +ve and -ve charge respectively
0%
d) of different e/m ratios
Explanation
Answer: (d)
Q.40
The electron configuration of a dipositive ion M2+is 2, 8, 14 and its mass number isthe number of neurons present is
0%
a)32
0%
b) 42
0%
c)30
0%
d)34
Explanation
Number of protons=2+8+14+2=26 Number of neutrons=56-26=30Answer: (c)
Q.41
The ion/molecule that is iso electronic with CO is
0%
a) CN-
0%
b) O22-
0%
c)N2+
0%
d)O2
Explanation
Number of electrons in CO=6+8=14Number of electrons in CN-=6+7+1=14Answer: (a)
Q.42
The number of electron having m=-1 in phosphorus atom is
0%
a) 3
0%
b) 4
0%
c)6
0%
d)9
Explanation
P , Z=15E.C. 1s2 2s2 2p6 3s2 3p3 For l=-1 is for 2p which is full thus 2 electron and 3p is half filled thus 1 electron total electrons=2+1=3 Answer:(a)
Q.43
A neutral atom of element has 2K, 8L, 11M and 2 N electrons. the total number of s-electrons in the atom is
0%
a) 8
0%
b) 2
0%
c) 16
0%
d) 11
Explanation
in each orbit there are two electrons for K, n=1 have one s-orbit,L, n=2 have one s-orbit and so on Answer: (a)
Q.44
In which of the following all the electrons are paired
0%
a)atom with atomic number 22
0%
b) nitride ion
0%
c)atom with configuration 3s2 3p4
0%
d)in all
Explanation
N3-=1 7 + 3=10 Configuration=as2 2s2 2p6 all are pairedAnswer: (b)
Q.45
The number of half filled orbitals in Fe3+ ion ( atomic number of Fe=26) is
0%
a) 3
0%
b) 4
0%
c)5
0%
d)6
Explanation
Fe3+ number of electrons=26-3=23Electron configuration [Ar] 3d5 Half filled orbitals 5Answer: (c)
Q.46
In the energy level sequence for multi-electron atom, 4f-orbital lies between
0%
a) 6s and 5d
0%
b) 5p and 5d
0%
c)4p and 5p
0%
d)5d and 6d
Explanation
( n+l) value for 4f=(4+3)=7(n+l) value for 6s=(6+0)=6 thus lower than 4f(n+l) value for 5d=(5+2)=7But value of n for 5d is higher than 4f Answer:(a)
Q.47
The correct electronic configuration of Fe3+ ion is Z=26
0%
a) [Ar]3d6
0%
b) [Ar]3d5
0%
c) [Ar]3d4
0%
d) [Ar]3d6, 4s2
Explanation
Z=26 for Fe and for Fe3+ number of electrons are 23Z for Ar=18, thus 23-18=5 electron in outer most orbit Answer: (b)
Q.48
The correct electron configuration for Ni2+ is (Z=28)
0%
a)[Ar]4s23d6
0%
b) [Ar]4s2 3d6
0%
c)[Ar]3d8
0%
d)[Ar]4s23d10
Explanation
Ni2+ have electrons=28-2=26 Aragon Ar have 18 electron thus electron in outer orbit=26-18=8 last orbit for Ar is 3p , actually 2 electrons should go to 4s but energy of 4s and 3d is similar, quantum number of 3d is smaller than 4s thus electrons goes in orbit of 3d Note while filling electrons it will follow abf-bau rule, above explanation is valid only for removal of electronsAnswer: (c)
Q.49
Which of the following is wrong?
0%
a) cathode rays have constant e/m ratio
0%
b) e/m ratio of anode rays is not constant
0%
c)e/m ratio of protons is not constant
0%
d)e/m ratio of β particles is constant
Explanation
Answer: (c)
Q.50
6Kr has the electron configuration as [Ar] 4s2 3d10 4pthe next 37th electron will go into the subshell
0%
a) 4d
0%
b) 4f
0%
c)5s
0%
d)6s
Explanation
Answer:(c)
0 h : 0 m : 1 s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Support mcqgeeks.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page