The half-life of iodine-131 is 8.1 days. How long will it take for three-fourths of a sample of iodine-131 to decay? (1-3/4 = 1/4; 1/4 = 1/2 x 1/2 = 2 half lives) will brainlist

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Arectangle has a diagonal 20 inches long that forms angles of 60 and 30 with the sides. find the perimeter of the rectangle. for geometry

Temperature is defined as a. the equivalent of heat. b. a measure of the average kinetic energy of the individual atoms or molecules composing a substance. c. how hot or cold it is. d. the total kinetic energy of the atoms or molecules composing a substance. e. none of the above is correct.