Q. 1. Which subatomic particle is absent in an ordinary hydrogen atom? Ans. Neutron. Q....

 Q. 1. How do you know that nucleus is very small as compared to the size of atom? Ans. Ruth...

Q. 1. List any three distinguishing features between the models of an atom proposed by J.J. Thomson...

 Q. 1. (i) State the method of determining the valency of an element if its atomic number is gi...