Metabolic activity in the human body releases approximately 1.0 × 104 kJ of heat per day. Assuming the body contains 50 kg of water, how fast would the body temperature rise if it were an isolated system? How much water must the body eliminate as perspiration to maintain the normal body temperature (98.6°F)? The heat of vaporization of water may be taken as 2.41 kJ/g. Comment on your results.
Notes March 15, 2016 - Photons (light-waves) are emitted from an atom when an electron moves from a higher energy level to a lower energy level o Energy = h x v - Photons can also be absorbed by an atom when an electron moves from a lower energy level to a higher energy level o Energy = h x v o SAME ENERGY LEVEL DIFFERENT (ex. 2 to 3 or 3 to 2) SAME PHOTON Identifying Atoms by Their Light - Spectroscopy – the study of light emitted or absorbed by an object at various wavelengths to determine its composition and physical state (e.g., temperature) - How a spectroscope works o A narrow slit focuses the light o A grating or a prism splits the light into its component colors - Emission spectrum of hydrogen (photons are emitting light, so electrons moving down) o Light at only some wavelengths o Blue, purple, green, and red = Hydrogen Emission Spectrum o Unique to hydrogen (like a barcode) o The red line is called “H alpha” - Different atom, different spectrum o Every element has its own spectrum o Note the differences between hydrogen and helium Helium = purple, blue, green, yellow, salmon, red - Absorption spectra (photons are absorbing energy, so electrons moving up) o Black lines where emission spectra have color; everywhere else has color - Summary of spectra o Continuous spectrum – the source emit
