To determine the element with the given information, we can start by finding the number of protons.
Since the cation has a 4+ charge, it means that it has lost 4 electrons from its neutral state. Therefore, if it currently has 18 electrons, the neutral atom of this element would have 18 + 4 = 22 electrons.
Atoms are electrically neutral, so the number of protons in the nucleus of an element is equal to its atomic number. Therefore, the atomic number of this element is 22.
We are also given that the element has 23 neutrons. The atomic mass of an element is the sum of the number of protons and neutrons in its nucleus. Thus, the atomic mass of this element would be 22 (protons) + 23 (neutrons) = 45.
To determine the specific element with these atomic number and mass number values, we can consult the periodic table. The element with atomic number 22 is titanium (Ti). Therefore, the cation with a 4+ charge, 23 neutrons, and 18 electrons is a titanium ion (Ti^4+).