Last seen: Jan 25, 2021
Bohr’s model of the atom (1) Atom has nucleus in the centre. (2) Electrons revolve around the nucleus. (3) Certain special orbits known as discr...
According to Rutherford’s model of an atom the electrons are revolving in a circular orbit around the nucleus. Any such particle that revolves would u...
According to J.J. Thomson’s model of an atom, the electrons are embedded all over in the positively charged spheres. But experiments done by other sci...
Electrons 1. Negatively charged. 2. Mass is negligible (1/1800 times of protons). 3. Get attracted towards +ve charge. 4. Present outside the ...
(d) 2,8,1 Explanation: Atomic number of sodium (Na) = 11 Its electronic configuration = 2, 8,1
(b) 8 Explanation: Electronic configuration of Cl (Z = 17) = 2, 8, 7. Thus, it has 7 valence electrons. Cl gains 1 electron to form CL ion. So, nu...
(c) different number of neutrons
1. F : Because it was not proposed by J.J. Thomson. 2. F : Because neutron is an independent sub-atomic particle. 3. T : Because it is a fact know...
Mass number of X = No. of protons + No. of neutrons = 6 + 6 = 12 Mass number of Y = 6 + 8 = 14 The species X and Y are isotopes because their ...
The electronic configuration of (Z) = 2,1 Thus, outermost shell has 1 electron. So, its valency = 1 Atomic number (Z) = 3, So name of the element is l...
Let the % of isotope = x and % of isotope = 100 -x Average atomic mass of an element (X) = 16.2 Average atomic mass = Mass of percentage of + ...
% of isotope = 49.7 % of isotope = 50.3 Average atomic mass of bromine atom = = = = 80.006 u
Atomic number of sodium (Na) = 11 No. of electrons in Na = 11 No. of electrons in Na+ = 11 - 1 = 10 Electronic configuration of Na+ → 2, 8 K ...
(i) Atomic number : The number of protons present in the nucleus of an atom is called atomic number. It is denoted by Z. e.g., in , atomic number = 20...
The number of electrons gained, lost or shared so as to complete the octet of electrons in valence shell is called valency. Valency of silicon : It ...
The distribution of elements in different orbits is governed by a scheme called Bohr- Bury scheme. There are following rules : The maximum numb...
The Danish physicist Neils Bohr proposed the following postulates for revising the Rutherford’s model. Atom has central nucleus surrounded by elec...
The Rutherford model suffers from the following drawbacks : (i) An electron revolving around the nucleus gets accelerated towards the nucleus. An ac...
The limitation of Thomson’s model are described below : Thomson’s model of an atom considers an atom to lae a sphere of uniform positive charge. L...