Problem page the half life for the radioactive decay of rubidium- to strontium- is years. suppose nuclear chemical analysis shows that there is of strontium- for every of rubidium- in a certain sample of rock. calculate the age of the rock. round your answer to significant digits

How does mass affect the speed of an object

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)

Which is an example of an exothermic process?