Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this

The answer is; D

Diffraction of light occurs when the light encounters an obstruction that is smaller than its wavelength. The water droplets in the clouds can be very small  and be closer in size to the wavelength of light. When sunlight encounters a cloud droplet, light waves are altered and interact with one another in a similar manner as the water waves causing fringes of light around clouds.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.