Number of valence electrons in Cl^- ion are

An atom contains 13 protons, 13 electrons and 14 neutrons, the mass number of that atom is

 Among the following which has a definite  shape?

The number of electrons gained, lost or shared so as to make the octet of electrons in the outermost shell, gives us directly the

The valency of argon is 

An atom contains 17 protons and 18 neutrons, the atomic number of that atom is 

An atom contains 14 protons and 14 neutrons, its atomic number is

The charge of a proton is 

The only one element does not contain neutron is

An isotope which is used in the treatment of goiter.