Answer :
The element is identified with the number of protons, and the element with 55 protons is Cs.
Since there are 54 electrons, the overall charge is +1, so the answer is [tex]\boxed{\text{Cs}^{+}}[/tex]
The element is identified with the number of protons, and the element with 55 protons is Cs.
Since there are 54 electrons, the overall charge is +1, so the answer is [tex]\boxed{\text{Cs}^{+}}[/tex]