half-life與activity

The answer is NO.

Half-life and activity are two independent physical quantities.
Examples are those radioactive sources commonly used in school physics laboratories. Most of them are of activities 200 kBq, but with varied half-lives, e.g. Cobalt-60 of half-life about 5.6 years, Americium-241 with half-life of about 246 years, Strontium-90 of half-life 29 years.