STRUCTURE OF ATOM Quiz-3

Chemistry Aptitude Quiz

Dear Readers,

IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies. Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..

Q1. Total binding energy of α-particles is

•  28.3 MeV
•  2.83 MeV
•  20.5 MeV
•   0.283 MeV

Solution

Q2.The energy of an electron in the first Bohr orbit for hydrogen is -13.6 eV. Which one of the following is a possible excited state for electron in Bohr orbit of hydrogen atom?

•  -3.4 eV
•  -6.8 eV
•  -1.7 eV
•  13.6 eV

Solution
(a)
E1=-13.6 eV
The possible excited state values are:
E_2=(-13.6)/4=-3.4 eV
E_3=(-13.6)/9=-1.5 eV
E_4=(-13.6)/16=-0.85 eV
So, the value is only -3.4 eV

Q3.  Rutherford’s experiment, which established the nuclear model of the atom, used a beam of

•  β-particles, which impinged on a metal foil and got absorbed
•  γ-rays, which impinged on a metal foil and ejected electrons
•  Helium atom, which impinged on a metal foil and got scattered
•  Helium nuclei, which impinged on a metal foil and got scattered

Solution
Part D

Q4.   The radiations from a naturally occurring radioactive substance, as seen after deflection by a magnet in one direction, are

•  Definitely alpha rays
•  Definitely beta rays
•  Both alpha and beta rays
•  Either alpha or beta rays

Solution

Part D

Q5.A radioisotope has half life of 10 years. What percentage of the original amount of it would you expect to remain after 20 years?

•  0
•  12.5
•  25
•  8

Solution
 

Q6. Which of the following nuclear reaction occurs in nature for the formation of tritium?

•   3 Li^6+〖 0 n〗^1→ 2 He^4+〖 1 H〗^3
•  〖 5 B〗^10+〖 0 n〗^1→2 2 He^4+〖 1 H〗^3
• 〖 7 N〗^14+〖 0 n〗^1→〖 6 C〗^12+〖 1 H〗^3
•   Be^9+〖 1 D〗^2→2 2 He^4+〖 1 H〗^3

Solution
Part C

Q7.The number of neutrons accompanying the formation of _54 Xe^139 and _38 Sr^94 from the absorption of a slow neutron by _92 U^235, followed by nuclear fission is

•  0
•  2
•  1
•  3

Solution
(d) 92 U^235+ 0 n^1→ 54 Xe^139 + 38 Sr^94+3 0 n^1

Q8.The first ionization potential in electron volts of nitrogen and oxygen atoms are, respectively, given by

•  14.6, 13.6
•  13.6, 14.6
•  13.6, 13.6
•  14.6, 14.6

Solution
(a)
Ionization potential of nitrogen is more that of oxygen. This is because nitrogen has more stable fully half-filled p orbitals

Q9.The most radioactive of the isotopes of an element is the one with the largest value of its

•  Half-life
•  Neutron number
•  Atomic number
•  Decay constant

Solution
(d)
-dN/dt=λ[A]
Greater the values of λ(decays constant) greater the activity

Q10. Which of the following statements about quantum numbers is wrong:

•  If the value of l=0, the electron distribution is spherical
•  The shape of the orbital is given by subsidiary quantum number
•  The Zeeman’s effect is explained by magnetic quantum number
• The spin quantum number gives the orientations of electron cloud

Solution
(d)
Spin does not give the orientation of electron cloud

Written by: AUTHORNAME

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