heluim are 4 nucleide

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern -UC---D-. That is, eight letter words with 2nd letter U and 3rd letter C and 7th letter D. In alphabetical order, they are:

cuckolds

nucleide

succeeds

I am assuming that by 'negative chlorine atom' you mean the ion, Cl- This has 17 Protons

18 electrons,

but the number of neutrons can vary, depending on the individual atom (which isotope)

On average there is 18 1/2, to give a Relative atomic mass of 35.45, so 18 or 19 neutrons, possibly others (I don't have a nucleide table sorry).

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern NU-L-I--. That is, eight letter words with 1st letter N and 2nd letter U and 4th letter L and 6th letter I. In alphabetical order, they are:

nucleide

nucleins

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 4 words with the pattern N-CL---E. That is, eight letter words with 1st letter N and 3rd letter C and 4th letter L and 8th letter E. In alphabetical order, they are:

nuclease

nucleate

nucleide

nucleole