The isotope of cobalt used in the treatment of cancer and iodine used in the treatment of goitre respectively are

The nucleus of a hydrogen atom is known as:

Fill in the blanks in the following statements:
$(a)$ Rutherford's $\alpha$-particle scattering experiment led to the discovery of the ............
$(b)$ Isotopes have same ............ but different .............
$(c)$ Neon and chlorine have atomic numbers $10$ and $17$ respectively. Their valencies will be ............ and ............. respectively.
$(d)$ The electronic configuration of silicon is .......... and that of sulphur is ...........

$(a)$ Write the names of three isotopes of hydrogen.
$(b)$ State one use of an isotope of uranium.
$(c)$ Isotopes of an element have similar chemical properties. Why?

Will $^{35}Cl$ and $^{37}Cl$ have different valencies? Justify your answer.

Give the salient features of Rutherford's nuclear model of the atom.