Dalton's atomic theory successfully explained:
$(i)$ Law of conservation of mass
$(ii)$ Law of constant composition
$(iii)$ Law of radioactivity
$(iv)$ Law of multiple proportions

$(a)$ Write two drawbacks of Rutherford's model of an atom.
$(b)$ State Bohr's postulates to overcome the drawbacks of Rutherford's model.

State whether the following statement is true or false:
The relative number and kinds of atoms are varying in a given compound.

In the Thomson's model of atom,which of the following statements are correct?
$(i)$ The mass of the atom is assumed to be uniformly distributed over the atom.
$(ii)$ The positive charge is assumed to be uniformly distributed over the atom.
$(iii)$ The electrons are uniformly distributed in the positively charged sphere.
$(iv)$ The electrons attract each other to stabilize the atom.

The isotope of uranium used as a fuel in nuclear reactors and carbon used in radiocarbon dating are

Give a brief account of the development of the presently accepted model of the atom with the contributions made by different scientists. Write two features of this atomic model.