Problem 37E
Which statement is true of the internal energy of a system and its surroundings during an energy exchange with a negative ΔEsys?
a. The internal energy of the system increases and the internal energy of the surroundings decreases.
b. The internal energy of both the system and the surroundings increases.
c. The internal energy of both the system and the surroundings decreases.
d. The internal energy of the system decreases and the internal energy of the surroundings increases.
Solution: The spectrum of hydrogen atom has played a very important role in the development of atomic structure. It can be obtained by passing an electric discharge through the gas taken in the discharge tube under low pressure. The emitted light is analysed with the help of spectroscope. The spectrum consists of a large number of lines appearing in different regions of wavelengths. The line spectrum observed in case of hydrogen atom can be quantitatively explained using Bohr’s model. When an electron jumps from a lower orbit to a higher orbit, it absorbs energy. When the electron jumps from higher orbit to lower orbit, it emits energy. Step1: a) When electron jumps from n = 4(higher orbit) to n = 2(lower orbit) energy level, energy is emitted. b) As we move from lower orbit to higher orbit, the distance between the nucleus and the orbit increases. As a result, the radii also increases. o So, when an electron jumps from an orbit of radius 2.12 A (lower orbit) to one of radius 8.46 A (higher orbit), energy is absorbed. c) When an electron is added to H ion, the starting point will be from n = state. Thus, when the added electron ends up in the n = 3 state, energy is released. --------------------
