The 2.5 Ohm ESR is typical for a B-case tantalum at this voltage and capacitance — expect it to handle moderate ripple current in bulk decoupling or output filtering roles without excessive self-heating.
Polarity and mounting
Yes, this is a polarized tantalum capacitor. The anode (+) is marked on the molded body; reverse voltage will damage the dielectric. Surface-mount in a 1411 (3528 Metric) / 1210 case — the 3.50 mm x 2.80 mm footprint with a seated height of 2.10 mm fits standard pick-and-place and reflow profiles.