The steady-state diffusion flux through a metal plate is 7.8 × 10-8 kg/m2-s at a temperature of 1220˚c ( 1493 k) and when the concentration gradient is -500 kg/m4. calculate the diffusion flux at 1000˚c ( 1273 k) for the same concentration gradient and assuming an activation energy for diffusion of 145,000 j/mol.

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

Observations show that interstellar clouds can have almost any shape and