Problem 35E

Suppose that a person eats 2387 Calories per day. Convert this amount of energy into each unit:

a. J

b. kJ

c. kWh

Solution: Here, we are going to explain how the existence of line spectra is consistent with Bohr’s theory of quantized energies for the electron in the hydrogen atom. Step1: Bohr observed that excited hydrogen atoms released certain specific energies, or different wavelengths (colors) in the spectrum. He realized that he could explain this phenomenon with "quantum" theory. According to Bohr, the electron in hydrogen atom can have energy values given by the relationship: Energy of the electron = -1311.8/ n kJmol , where n = 1, 2, 3, 4 …. In other words, n cannot have fractional values so that the electron cannot have all possible values of energy but only those values for which n is a whole number. Thus, electron can take only certain fixed values of energy. It means that when an electron gains or loses energy, it does so in such a way that n has a value which is a whole number. In other words, electron does not gain or lose energy in a continuous manner but in jumps(or bursts). This led to the concept of quantisation of energy which means that radiant energy is emitted or absorbed in bursts rather than as continuous flow. ---------------------