A certain radioactive isotope decays at a rate of 85% hourly. Determine the half-life of this isotope to the nearest minute. Use the formula A = lekt where A is the amount at time t, I is the initial amount, and k is the decay constant unique to the substance. a. 256 min
b. 14 min
c. 22 min
d. 18 min
e. 35 min

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17

Select the correct answer. wax is a nonpolar substance. in which type of substance is it the most soluble?

How does the digestive system interact with the circulatory system? a. messages sent as electrical impulses from the digestive system are transported throughout the body by the circulatory system. b. nutrients taken in and broken down by the digestive system are carried to various parts of the body by the circulatory system. c. nutrients and gases are absorbed by organs in the circulatory system. then, they are transported to all parts of the body by organs in the digestive system. d. oxygen and carbon dioxide are exchanged by organs in the digestive system, and the gases are carried to the rest of the body by the circulatory system.