What is the half-life of a 3 g sample of radioisotope that decayed to 0.75 g in 30 days?

Which of the following would not diffuse through the plasma membrane by means of simple diffusion? 1 oxygen 2 glucose 3 a steroid hormone 4 a lipid soluble vitamin

Which statement best describes the liquid state of matter? a. it has definite shape but indefinite volume. b. it has definite shape and definite volume. c. it has indefinite shape and indefinite volume. d. it has indefinite shape but definite volume.

Jenny wants to test the electrical conductivity of two substances dissolved in water. she is preparing the containers for the experiment. which factor is most important for her to control?