salt(NaCl) ge salty taste 係來自邊度??

"Taste" is a physiological response of the mouth, tongue, and throat.
"Taste" also involves odor as well but that is even more complicated
and not well understood. The mouth, tongue, throat produces a
physiological response by "receptors" located in various parts. So
NaCl, NaBr, NaI have a different "taste" because the physiological
response depends upon the presence of both ions. So, LiCl, NaCl,
KCl, RbCl, CsCl also have a different "taste" even though the anion
is the same. So "salty" is not so much related to a phase change but
rather to a complicated signal sent from the mouth, tongue, throat
to the brain that depends upon both the cation and anion. Of course,
this interaction also occurs with other cations such as Mg, Ca and
anions such as (SO4), (PO4) etc.

The precise mechanism is not well understood. BUT DO NOT
experiment with a "taste test" because some of these combinations
may be toxic as well.

You' ve only answered in an upper surface, I still cannot understand why will salt be tasted as salty.
I think you may reply in great detail.

The salty taste is mainly from the chloride ion. That's why some table salt for hypertension (血壓高) patients has replaced the certain amount of sodium chloride to potassium chloride since too much sodium is not good for the patients. However, this salt still gives a salty taste. Of course, the salty taste can be slightly altered in the presence of other ions. Therefore, in some restaurants such Steak House in Intercontinental Hotel in TST, they offer different kinds of salt for the steak. With the trace amont of different ions in the various salt, the salt taste a bit differen. However, the main ingredient gives the salty taste is the chlroide ion.