Calculate H for the reaction H2(g) 1 I2(g) 2HI(g) using (a) Equation (9.3) and (b) Equation (6.18), given that Hf for I2(g) is 61.0 kJ/mol.

CHEM 211 CH. 7- Quantum Theory and Atomic Structure The Wave Nature of Light The wave properties of electromagnetic radiation are described by three variables: -frequency- cycles per second -wavelength- the distance a wave travels in one cycle -amplitude- the height of a wave crest or depth of a trough *the speed of light is a constant: =3.00*10^8 m/s in a vacuum Energy and Frequency A solid object emits visible light when it is heated to about 1000 K. This is called blackbody radiation The color (and the intensity) of the light changes as the temp. changes. Color is related to wavelength and frequency, while temperature is related to energy Planck proposed that one certain quantities of energy can be emitted (or absorbed) The Quantum Theory of Energy Any object (including atom