Atomic Nucleus MCQs
According to the Rutherford’s atomic model atom consists of a central core called as Nucleus. The Nucleus is positively charged core of very high density. The nucleus consists of the protons and neutrons. Number of protons present in the nucleus is known as atomic number (Z), and the sum of numbers of protons and neutrons in nucleus is known as atomic mass or mass number (Z). The protons and neutrons are the constituents of nucleus hence known as nucleons. For all nuclei naturally present in the Universe, Z varies from 1 to 92, and A from 1 to 238.
Q.1) The radius of nuclei is given as…..
Q.2) The density of an atomic nucleus is about…
a) 3 x 1017 kg/m3.
b) 2.3 x 1017 kg/m3.
c) 3 x 1017 kg/m3.
d) 3 x 1017 kg/m3.
Q.3) The nuclei having same atomic number but different mass number is known as…
a) Isobars
b) Isotones
c) Isotopes
d) None of these.
Q.4) The nuclei having same mass number but different atomic number is known as…
a) Isobars
b) Isotones
c) Isotopes
d) None of these.
Q.5) Radius of an atom with atomic number of 125 is…….
Q.6) How many neutrons are present in a nucleus of mass number 235 with 92 protons?
a) 92
b) 327
c) 143
d) 235
Here, No of neutrons= mass number – number of protons
No of neutrons= 235 – 92=143
Q.7) The process of spontaneous disintegration of mass of nucleus is known as…
a) Nuclear decay
b) Nuclear fission
c) Nuclear fusion
d) Radioactivity
Q.8) About …….. of mass of an atom is concentrated in nucleus.
a) 50%
b) 75%
c) 99%
d) 100%
Q.9) The strongest force among the following is……….
a) Gravitational force
b) Electrostatic force
c) Magnetic force
d) Nuclear force
Q.10)The mass of protons is nearly……….times that of mass of electron.
a) 1836
b) 1736
c) 1636
d) 1536
Answers:
Q.1.) a R = RoA1/3
Q.2) b) 2.3 x 1017 kg/m3.
Q.3) c) Isotopes
Q.4) a) Isobars
Q.5) d) 6 x 10-15
Q.6) c) 143
Q.7) d) Radioactivity
Q.8) c) 99%
Q.9) d) Nuclear force
Q.10) a) 1836
