Final answer:
Without the half-life of Hassium-265, it is impossible to determine how much of a 256-gram sample will remain after 8 seconds. Additional information is necessary to accurately answer the question.
Step-by-step explanation:
If you start with a 256–g sample of Hassium-265 and want to know how much will be left after 8 seconds, you would need to know the half-life of Hassium-265. Unfortunately, the half-life for Hassium-265 is not provided in the question, making it impossible to calculate without additional information.
If the half-life were provided and it was 2 seconds, for example, you'd expect half the material to decay every 2 seconds. After 2 seconds, you'd have 128 grams remaining, after another 2 seconds (4 seconds total), you'd have 64 grams, and 8 seconds total would leave you with 32 grams. But without the half-life, it's impossible to answer the question definitively.
It's important to have all necessary information, like the half-life, to solve this type of problem accurately. Without it, any answer given would be a guess and not factually accurate.