The half-life of strontium-90 is 28 years. How long will it take a 80-mg sample to decay to a mass of 51.2 mg

Your awser would be a acetone

The population of unionid mussels decreased after zebra mussels were introduced. zebra mussels competed with the unionid mussels for food. the zebra mussels were able to displace the unionid mussels, allowing the zebra mussel population to increase  over the years. the unionid mussel population decreased because  of lack of food.

Ithink the answer is 10.576

1. i don't know.2. bitter taste, feels slippery, contains hydroxide or produces it in a solution.3. 104.i don't know.5. electrons.hope this somewhat!