Au-198 with half life of 2.7days after after 5.4 days

1/4th the mass of Au-198

Explanation:

A half-life of 2.7 days means that in 2.7 days half of the Au-198 will be gone. This means that after 5.4 days, the amount of Au-198 will have undergone two half-life cycles resulting in there being 1/4th the amount of Au-198 left from the starting amount.

the answer for sodium is 0.186

the answer for rubidium is 0.251

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".