Tc7+ is very strongly acidic and will exist as an oxo anion in the form
TcO4-
Recall for MOxy-:
pKb1 = 10.0 + 5.7x - 10.2y
pKb1 = 10.0 + 5.7(4) - 10.2(1)
pKb1 = 22.6
 =>  this is non basic and will persist in water
Alternately: formula evaluation yields "TcO2" which is non basic.
Feebly basic anions would also persist in solution; moderately basic anions would be partially protonated;
very strongly basic oxo anions will probably be protonated beyond the hydroxo anion stage often forming
an insoluble hydroxide or oxide.