If a mineral has a daughter to parent ratio of 3: 1 (three daughter atoms for every one parent atom), how many half lives have passed since the mineral formed

25% means has 2 halflives old.

The rock is 57 million years, which would be multiplied to 2(halflives) = 114 million years old.

Therefore, the halflives of the mineral formed is 2 and 1 halflife there is a total of 57 million years.

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".