The atomic number of an element never changes no matter how many neutrons they have so Sulfur would just have an atomic number of 16 like normal.
Yes, S-blocks are metals except for helium and hydrogen. The S-block metals are shiny, silvery and relatively soft, although they can easily lose electrons. Helium and hydrogen have valence electrons but also lack some similar properties as the other metals.
Pure water is called distilled water or deionized water.
Atomic radio increases as number of valence electrons increase. Hence the first and fourth statement are wrong. Electronegativity is highest for elements on the TOP right hand corner of the periodic table so the third statement is wrong. Hence the answer is the third statement