Which is NOT an example of evidence that shows a chemical reaction occurred? change in color
change in temperature
change in shape
bubbles, fizzing

How have the competing explanations' experiments on atoms affected the development of the atomic model?

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 hz? planck’s constant is 6.63 × 10–34

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.