Question

1. because excited hydrogen atoms always produce the same emission spectrum, bohr concluded that hydrogen

a. had no electrons.
b. did not release photons.
c. released photons of only certain fixed energies.
d. could only exist in the ground state.

1. when the pink - colored light of energized hydrogen gas passes through a prism, it is possible to see

a. all the colors of the rainbow. c. four lines of different visible light
b. only lavender - colored lines. d. all black light.

1. a hue of violet light measures ( 7.50\times10^{14} ) waves/second. how much energy does a photon of this light have?

a. ( 1.13\times10^{48}j ) c. ( 8.83\times10^{-49}j )
b. ( 4.97\times10^{-19}j ) d. ( 2.25\times10^{-23}j )

1. the distance between 2 crests of electromagnetic radiation is its

a. frequency. c. quantum number.
b. wavelength. d. amplitude.

1. electricity is passed through a tube of hydrogen gas. viewing the light given off by the bulb through a prism

or spectrometer displays specific wavelengths of light called the:
a. line - emission spectrum. c. photoelectric effect.
b. light bulb effect d. continuous electromagnetic spectrum.

1. a quantum of electromagnetic energy is called a(n)

a. photon. c. excited atom.
b. electron. d. orbital.

1. as wavelength of a light wave increases, what happens to its energy?

a. increases
b. decreases
c. stays constant
d. unrelated properties.

1. according to the bohr model of the atom, the single electron of a hydrogen atom circles the nucleus

a. in specific, fixed orbits only.
b. in one fixed orbit at all times.
c. anywhere in the electron cloud.
d. counterclockwise.

Explanation:

1. Bohr's model of the atom proposed that electrons in hydrogen atoms can only occupy certain discrete energy levels. When excited electrons return to lower energy levels, they emit photons with specific energies corresponding to the energy differences between the levels. This explains why excited hydrogen atoms always produce the same emission spectrum (fixed - energy photons).
2. The emission spectrum of hydrogen gas consists of discrete lines in the visible region. The most well - known are the Balmer series, which has four prominent lines in the visible spectrum (red, blue - green, blue, and violet).
3. The energy of a photon is given by the formula \(E = h

u\), where \(h = 6.626\times10^{-34}\space J\cdot s\) (Planck's constant) and \(
u\) is the frequency. Given \(
u=7.50\times 10^{14}\space s^{-1}\), then \(E=(6.626\times 10^{-34}\space J\cdot s)\times(7.50\times 10^{14}\space s^{-1}) = 4.97\times 10^{-19}\space J\) (using \(E = h
u\) and plugging in the values).

1. The wavelength of an electromagnetic wave is defined as the distance between two consecutive crests (or troughs). Frequency is the number of waves passing a point per second, the quantum number is a set of values that describe the state of an electron in an atom, and amplitude is the height of the wave from the mid - line.
2. When electricity is passed through hydrogen gas, the excited hydrogen atoms emit light at specific wavelengths. This is called the line - emission spectrum. The photoelectric effect is the ejection of electrons from a metal surface when light of a certain frequency shines on it, and a continuous electromagnetic spectrum has a continuous range of wavelengths (like white light).
3. A photon is the quantum (discrete packet) of electromagnetic energy. An electron is a sub - atomic particle, an excited atom is an atom with electrons in higher energy levels than the ground state, and an orbital is a region in an atom where an electron is likely to be found.
4. The energy of a photon is inversely related to its wavelength (\(E=\frac{hc}{\lambda}\), where \(h\) is Planck's constant and \(c\) is the speed of light). As the wavelength \(\lambda\) increases, the energy \(E\) decreases.
5. In the Bohr model of the atom, the electron of a hydrogen atom moves in specific, circular orbits around the nucleus. These orbits have fixed radii and energies. The electron can jump between these orbits by absorbing or emitting photons of specific energies.

Answer:

1. C. released photons of only certain fixed energies.
2. C. four lines of different visible light.
3. B. \(4.97\times 10^{-19}\space J\)
4. B. wavelength.
5. A. line - emission spectrum.
6. A. photon.
7. B. decreases.
8. A. in specific, fixed orbits only.