Shade all the elements for which the neutral atom has a valence electron configuration of ns2np6 , where n stands for an integer.

The elements for which the neutral atom has a valence electron configuration of .



are those whose valence electron shell has 2 + 6 = 8 electrons.

Those are the noble gases, except helium (He).

Here is the list of the noble gases and the configuration of their valence electron configuration:

He:    

Ne     

Ar      

Kr      

Xe      

Rn     

Ne, Ar, Kr, Xe and Rn

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.