Advertisements
Advertisements
प्रश्न
What do you mean by polar molecules and non-polar molecules? Give ‘one’ example each.
उत्तर
Polar molecules: The molecules in which “centre of gravity” of positive nuclei and revolving electrons do not coincide are known as polar molecules.
Example: HCl, H2O, N2O etc.
Polar substances behave as a tiny electric dipole because polar molecules have a permanent electric dipole moment.
Non-polar molecules: The molecules in which “centre of gravity” of positive nuclei and revolving electrons coincide are known as non-polar molecules.
Example: O2, H2, CO2, polyethelene, polystyrene etc.
Non-polar molecules do not have permanent electric dipole moment because of their
symmetry.
APPEARS IN
संबंधित प्रश्न
A nucleus with mass number A = 240 and BE/A = 7.6 MeV breaks into two fragments, each of A = 120 with BE/A = 8.5 MeV. Calculate the released energy.
In the study of Geiger-Marsdon experiment on scattering of α particles by a thin foil of gold, draw the trajectory of α-particles in the coulomb field of target nucleus. Explain briefly how one gets the information on the size of the nucleus from this study.
From the relation R = R0 A1/3, where R0 is constant and A is the mass number of the nucleus, show that nuclear matter density is independent of A
Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of `""_88^226 "Ra"`.
Given `"m"(""_88^226"Ra")` = 226.02540 u, `"m"(""_86^222 "Rn")` = 222.01750 u,
`"m"(""_86^220 "Rn")`= 220.01137 u, `"m"(""_84^216 "Po")`= 216.00189 u.
The nucleus `""_10^23"Ne"` decays by `beta^(-)`emission. Write down the β decay equation and determine the maximum kinetic energy of the electrons emitted. Given that:
`"m"(""_10^23 "Ne")` = 22.994466 u
`"m"(""_11^23 "Na")` = 22.989770 u.
With the help of a suitable example and an equation, explain the term pair production.
Show that the density of nucleus over a wide range of nuclei is constant-independent of mass number A.
Two nuclei have mass numbers in the ratio 1: 2. What is the ratio of their nuclear densities?
The atomic mass of Uranium `""_92^238"U"` is 238.0508 u, while that of Thorium `""_90^234"Th"` is 234.0436u, and that of Helium `""_2^4"He"` "is 4.0026u. Alpha decay converts `""_92^238"U"` into `""_92^234"Th"` as, shown below:
`""_92^238"U" -> ( ""_90^234"Th" + ""_2^4"He" + "Energy" )`
Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of `""_86^220"Rn"`.
Given `"m"(""_88^226"Ra")` = 226.02540 u, `"m"(""_86^222 "Rn")` = 222.01750 u,
`"m"(""_86^220 "Rn")`= 220.01137 u, `"m"(""_84^216 "Po")`= 216.00189 u.
Atomic mass unit (u) is defined as ________ of the mass of the carbon (12C) atom.
\[\ce{^197_79Au}\] contains ______.
The nuclei of isotopes of a given element contain the same number of ______.
All nuclides with same mass number A are called ______.
Nuclides with same neutron number N but different atomic number Z are called ______.
A nucleus yYx emits one α and two β particles. The resulting nucleus is ______.
A nuclide 1 is said to be the mirror isobar of nuclide 2 if Z1 = N2 and Z2 = N1. (a) What nuclide is a mirror isobar of 1123 Na? (b) Which nuclide out of the two mirror isobars have greater binding energy and why?
Deuteron is a bound state of a neutron and a proton with a binding energy B = 2.2 MeV. A γ-ray of energy E is aimed at a deuteron nucleus to try to break it into a (neutron + proton) such that the n and p move in the direction of the incident γ-ray. If E = B, show that this cannot happen. Hence calculate how much bigger than B must E be for such a process to happen.
Distinguish between isotopes and isobars.
Two nuclei have different mass numbers A1 and A2. Are these nuclei necessarily the isotopes of the same element? Explain.
James Chadwick, in 1932 studied the emission of neutral radiations when Beryllium nuclei were bombarded with alpha particles. He concluded that emitted radiations were neutrons and not photons. Explain.
Two nuclei may have the same radius, even though they contain different numbers of protons and neutrons. Explain.
Which of the following are the constituents of the nucleus?
What conclusion is drawn from Rutherford’s scattering experiment of α-particles?
What is 'Pair production'?
