The surface of a solid sphere is covered by a monolayer of receptors for a ligand. When the ligands diffuse to the surface of the sphere, they are captured instantaneously by the receptors. The ligand diffusion coefficient is 5.2*10-9m2/s. Assume the bulk concentration far away from the sphere is constant of 6.6 nM and the sphere radius is 9.8 μm. (a) Find the ligand concentration C at the location of r=4.9 μm at steady state, where r is the distance to the surface of the sphere. Please enter the numerical value with a unit of nM.

In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. which postulate of kinetic molecular theory best explains how this is possible? a. attractive forces between gas particles are negligible because the particles of an ideal gas are moving so quickly. b. collisions between gas particles are elastic; there is no net gain or loss of kinetic energy. c. gases consist of a large number of small particles, with a lot of space between the particles. d. gas particles are in constant, random motion, and higher kinetic energy means faster movement.

How does a scientist the government? a. the scientist tells people in society what to do. b. the scientist determines the policies that the government spends money on. c. the scientist provides unbiased information to the government. d. the scientist makes laws based on his or her research results.

Explain what happens at the saturation point when adding salt to water at room temperature.