☰
The Fundamental Unit of Life
Who discovered neutrons? What observation lead to the discovery of neutrons?
Chadwick discovered neutrons. The observation that the atomic masses of elements other than hydrogen could not be explained on the basis of the presence of only protons and electrons in an atom, and the atomic masses of all elements are much higher than that expected on the basis of the presence of only protons and electrons in an atom led to the discovery of neutron.
Sponsor Area
What are the limitations of Rutherford model of the atom?
Describe Bohr's model of the atom ?
Compare all the proposed models of an atom given in this chapter.
Summarize the rules for writing of distribution of electrons in various shells for the first eighteen elements.
Define valency by taking examples of silicon and oxygen.
Explain with examples, (i) Atomic number, (ii) Mass number, (iii) Isotopes, and (iv) Isobars. Give any two uses of isotopes also.
Na+ has completely filled K and L-shells. Explain.
If Z = 3, what would be the valency of the element? Also, name the element.
Composition of the nuclei of two atomic species X and Y are given as under
X Y
Protons = 6 6
Neutrons= 6 6
Give the mass numbers of X and Y. What is the relation between the two species?
Sponsor Area
Sponsor Area