________________ proposed a theory of atom known as the atomic theory.

_________________ discovered the positive rays emitted the anode.

______________ was an ancient greeck philosopher studied the nature of the matter and the basic constituents of all substance.

According to ______________ atomic theory an atom is the smallest unit of matter which takes part in a chemical reaction

________________ is the electrons in its valence shell forming an anion.

According to _______________ atomic theory atoms are neither created nor destroyed.

_____________________ is the electronic configuration of nitrogen atom.

Uranium has ________________ isotopes.

Oxygen has_________ isotopes.

_______________ discovered that cathode rays have kinetic energy and raise the temperature of a metallic object on which they fall.