A mole of iron is therefore 55.845 grams. Quick conversion of 1 cubic foot to liters gives us 28.32 liters. Going back we can take this number to find that 28.32 liters of gas at STP is going to be 1.26414494 moles of air. Great, we can now determine how many moles of each particular substance we have from the percentage composition of air.
X-rays are attenuated as they pass through matter. That is, the intensity of an X-ray beam decreases the farther it penetrates into matter. Basically, each interaction of an X-ray photon with an atom of the material removes an X-ray from the beam, decreasing its intensity.
The intensity of a wave is proportional to the square of the amplitude of the AND the frequency of the wave given by the equation: Now when talking about sound waves the sound level of a noise (loudness), it is proportional to the intensity of the source. If intensity of a wave is proportional to frequency, why doesn't sound level, in general, depend on frequency. i.e. Higher frequency, higher intensity, higher sound level. Why is this not the case?