The true statements about ions are:
A. Ions have different numbers of protons than the original atoms. (This is incorrect; ions have the same number of protons as the original atoms but a different number of electrons).
B. Ions are no longer neutral compared to original atoms. (This is correct; ions have an overall charge due to the loss or gain of electrons, making them charged and thus not neutral.)
C. Ions are always less stable than atoms. (This statement is not true; whether an ion is more or less stable than its neutral atom depends on the specific context. Some ions can be more stable in certain conditions, such as when they achieve a stable electronic configuration.)
D. Ions are no longer neutral compared to original atoms. (This is correct; it essentially repeats statement B.)
So the correct answers are B and D.