Q.9:- Na+ has completely filled K and L shells. Explain. Answer:- Atomic number of sodium (Na) = 11 No. of electrons in Na = 11 No. of electrons in Na+ =…
Q.9:- Na+ has completely filled K and L shells. Explain. Answer:- Atomic number of sodium (Na) = 11 No. of electrons in Na = 11 No. of electrons in Na+ =…
Q.8:- Explain with examples (i) Atomic number, (ii) Mass number, (iii) Isotopes and (iv) Isobars. Give any two uses of isotopes. Answer:- (i) Atomic Number : The number of…
Q.7:- Define valency by taking examples of silicon and oxygen. Answer:- The number of electrons gained, lost or shared so as to complete the octet of electrons in valence…
Q.6:- Summarize the rules for writing the distribution of electrons in various shells for the first eighteen elements. Answer:- The distribution of elements in different orbits is governed by…
Q.5:- Compare all the proposed models of an atom given in this chapter. Answer:- 1. J.J. Thomson’s model of atom (i) An atom consists of a sphere of positive…
Q.4:- Describe Bohr’s model of the atom. Answer:- The Danish physicist Neils Bohr proposed the following postulates for revising the Rutherford’s model. (a) Atom has central nucleus surrounded by…
Q.3:- What are the limitations of Rutherford’s model of the atom? Answer:- The limitations of Rutherford’s model of the atom are following: (a) It does not explain the stability…
Q.2:- What are the limitations of J.J. Thomson’s model of the atom? Answer:- The limitations of J.J Thomson’s model of an atom are following: (a) It could not explain…
Q.1:- Compare the properties of electrons, protons and neutrons. Answer:- Property Electron Proton Neutron 1. Symbol or or or 2. Charge -1 unit or + 1 unit…
Q.:- Write the electronic configuration of any one pair of isotopes and isobars. Answer:- Isotope of chloride: Electronic configuration of each of them : 2, 8, 7 Isobars…