An ion is has 5 proton, 7 nuetron, 3+ of what

Normally an atom would have the same number of proton and electron in order to be neutral. But an ion has a charge either positive or negative. 3+ meaning that the ion is positive and have 3 less electron compared to the proton. So this ion has 5 proton and 2 electron.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.