Question

a certain particle x has 17 protons 18 electrons and 20 neutrons
1-what is such a particle called?

Answer 1

$$\begin{gathered} TheparticleXhas17protons,soitsatomicnumberis17. \\ Thenumberofelectron=18.Soitexistasnegativeion. \\ Massno=noofproton+noofneutron=17+20=37 \\ SotheelementischlroineanditexistinthiscaseaschlorideionC{l}^{-} \end{gathered}$$