12. What is the frequency of a photon with an energy of 3.03 x 10-19 J? (Planck's constant: h=6.63x 10-34 J·s) (E =hu)
a. 1.98x10^-18 Hz
b. 4.58x10^14 Hz
c. 2.16x10^14 Hz
d. 4.39x10^-19 Hz

This chart represents the melting point of several substance. what besy explains the high melting point of the salt?

In an exothermic reaction the bonding energy of the product is: less than the reactants same as the reactants greater than the reactants dependent upon the presence of a catalyst

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.