Question 1

The energy contained in a length of a 3.00-mW laser beam in vacuum is 1.80 * 10^-10 J.What is the length of the beam?

Accepted Answer

D

Question 2

How much energy is contained in a 3.00-mW laser beam of length 2.00 m that moves through vacuum?

Accepted Answer

The energy in a laser beam is given by the product of its power and the time it takes to travel a certain distance. In this case, the power is 3.00 mW, which is equal to 3.00 * 10^-3 W, and the distance is 2.00 m. The time it takes the beam to travel this distance is equal to the distance divided by the speed of light, which is approximately 3 * 10^8 m/s. Therefore, the time it takes the beam to travel 2.00 m is approximately 6.67 * 10^-9 s. The energy in the beam is then equal to the power multiplied by the time, which is (3.00 * 10^-3 W) * (6.67 * 10^-9 s) = 2.00 * 10^-11 J.

Question 3

The energy contained in laser beam of length 2.00 m that moves through vacuum is 1.80 * 10^-10 J.What is the power of the laser?

Accepted Answer

D

Question 4

The wavelength of the  line of the Lyman group for the hydrogen spectrum is

Accepted Answer

The answer of The wavelength of the  line of...

Question 5

The energy required to ionize hydrogen when the electron is in the second level is _______ the energy required to ionize hydrogen when electron is in the first level.

Accepted Answer

The energy required to ionize an electron from a hydrogen atom is inversely proportional to the square of the principal quantum number (n). For n=1, the energy is 13.6 eV, and for n=2, it is 13.6/4 = 3.4 eV, which is one fourth of the energy required for n=1.

Question 6

If the period of rotation of electron in the Bohr hydrogen atom is 4.10 fs,which Bohr orbit does the electron occupy?

Accepted Answer

The period of rotation of an electron in a Bohr orbit is given by $T_n = \frac{2\pi n^3 h}{Zke^2}$, where $n$ is the principal quantum number (or the orbit number), $h$ is Planck's constant, $Z$ is the atomic number (which is 1 for hydrogen), $k$ is Coulomb's constant, and $e$ is the charge of an electron. Given the period $T = 4.10$ fs, we can solve for $n$ using the formula. The calculation shows that the electron occupies the third orbit.

Question 7

The period of rotation of electron on the 6-th Bohr orbit is __________ the period of rotation of electron on the 3- rd Bohr orbit.

Accepted Answer

The period of rotation of an electron in a Bohr orbit is proportional to the cube of the principal quantum number (n^3). Therefore, for the 6th orbit (n=6) compared to the 3rd orbit (n=3), the period of rotation is (6^3)/(3^3) = 216/27 = 8 times longer.

Question 8

The electron in a singly ionized helium atom,which consists of two protons,two neutrons and only one electron,makes a transition from the n = 2 state to the n = 1 state,emitting a single photon in the process.What is the energy of this photon?

Accepted Answer

The energy levels of a hydrogen-like atom are given by the formula E_n = -13.6 Z^2 / n^2 eV, where Z is the atomic number. For helium (Z=2), the energy of the n=2 state is -13.6 * 4 / 4 = -13.6 eV, and the n=1 state is -13.6 * 4 / 1 = -54.4 eV. The energy of the photon emitted is the difference: 54.4 - 13.6 = 40.8 eV.

Question 9

The wavelength of the  line of the Balmer group for the hydrogen spectrum is

Accepted Answer

The Balmer series is a series of hydrogen spectral lines produced by electron transitions from energy levels n ≥ 3 to n = 2. The 11ea821f_c64c_2fc1_bbd8_791f6eb945fc_TB1516_11_TB1516_11_TB1516_11 line corresponds to the transition from n = 4 to n = 2. The formula for calculating the wavelength of these lines is λ = 1.097 × 10^-2 (1/2^2 - 1/n^2), where n is the energy level of the electron. Plugging in n = 2 and n = 4, we get λ = 434 nm. Therefore, the correct answer is D.

Question 10

A photon needed to excite an electron from the  to the  state.What is the energy of the photon?

Accepted Answer

The answer of A photon needed to excite an electron...

Question 11

The frequency of the  line of the Lyman group for the hydrogen spectrum is

Accepted Answer

The answer of The frequency of the  line of...

Question 12

Positronium consists of a bound state of an electron and a positron.A positron is exactly the same as an electron,except it has a charge of +e instead of -e.In the classical model,both particles orbit a point midway between them.The reduced mass of positronium is equal to

Accepted Answer

The answer of Positronium consists of a bound state of...

Question 13

The Bohr model of hydrogen is based on the quantization of

Accepted Answer

The Bohr model of hydrogen is based on the quantization of orbital angular momentum. This means that the electron in a hydrogen atom can only occupy certain shells with specific energy levels. The Bohr model was developed to explain the line spectrum of hydrogen, which showed discrete wavelengths of light corresponding to specific energy transitions. The quantization of orbital angular momentum was crucial to explaining why these discrete energy transitions occurred.

Question 14

The minimum orbital angular momentum quantum number for the  is

Accepted Answer

The answer of The minimum orbital angular momentum quantum number...

Question 15

The frequency of the  line of the Balmer group for the hydrogen spectrum is

Accepted Answer

The answer of The frequency of the  line of...

Question 16

The electron in a singly ionized helium atom,which consists of two protons,two neutrons and only one electron,makes a transition from the n = 2 state to the n = 1 state,emitting a single photon in the process.What is the energy of this photon?

Accepted Answer

The energy of the photon emitted during the transition can be calculated using the formula for the energy levels of a hydrogen-like atom, $E_n = -\frac{Z^2 \cdot 13.6 \text{ eV}}{n^2}$, where $Z$ is the atomic number (for helium, $Z=2$) and $n$ is the principal quantum number. The energy difference ($\Delta E$) between two levels is given by $\Delta E = E_2 - E_1$, where $E_2$ and $E_1$ are the energies of the final and initial states, respectively. For a transition from $n=2$ to $n=1$, the energy of the emitted photon for a singly ionized helium atom (He$^+$) is $\Delta E = -\frac{4 \cdot 13.6 \text{ eV}}{1^2} - \left(-\frac{4 \cdot 13.6 \text{ eV}}{2^2}\right) = -54.4 \text{ eV} + 13.6 \text{ eV} = -40.8 \text{ eV}$. The positive value of 40.8 eV (since we are interested in the magnitude of energy released) is not listed among the options, making all provided choices incorrect.

Question 17

An electron in the hydrogen atom makes a transition from the  state to an nth state.The electron gains 0.50 eV of energy.What value of  is the final state of the electron?

Accepted Answer

The answer of An electron in the hydrogen atom makes...

Question 18

The period of rotation of electron on the second Bohr orbit is

Accepted Answer

The period of rotation of an electron on the nth Bohr orbit is given by T=2π(n²h/μe²), where h is Planck's constant, μ is the reduced mass of the electron and the nucleus, and e is the elementary charge. For the second Bohr orbit (n=2), we have T=2π(2²h/μe²)=1.22 fs. Therefore, the correct answer is B.

Question 19

The maximum orbital angular momentum quantum number for the  is

Accepted Answer

The answer of The maximum orbital angular momentum quantum number...

Question 20

In the Bohr model of hydrogen,as the principle quantum number n increases,

Accepted Answer

In the Bohr model, as the principal quantum number $n$ increases, the total energy of the electron becomes less negative (indicating an increase in total energy), the kinetic energy decreases because the electron is moving in a larger orbit at a slower speed, the potential energy increases (becoming less negative) due to the electron being further from the nucleus, and the orbital radius increases. This means all the given statements are correct in the context of the Bohr model.

Quiz 38: Atomic Physics

The energy contained in a length of a 3.00-mW laser beam in vacuum is 1.80 * 10-10 J.What is the length of the beam?

How much energy is contained in a 3.00-mW laser beam of length 2.00 m that moves through vacuum?

The energy contained in laser beam of length 2.00 m that moves through vacuum is 1.80 * 10-10 J.What is the power of the laser?

The wavelength of the line of the Lyman group for the hydrogen spectrum is

The energy required to ionize hydrogen when the electron is in the second level is _______ the energy required to ionize hydrogen when electron is in the first level.

If the period of rotation of electron in the Bohr hydrogen atom is 4.10 fs,which Bohr orbit does the electron occupy?

The period of rotation of electron on the 6-th Bohr orbit is __________ the period of rotation of electron on the 3- rd Bohr orbit.

The electron in a singly ionized helium atom,which consists of two protons,two neutrons and only one electron,makes a transition from the n = 2 state to the n = 1 state,emitting a single photon in the process.What is the energy of this photon?

The wavelength of the line of the Balmer group for the hydrogen spectrum is

A photon needed to excite an electron from the to the state.What is the energy of the photon?

The frequency of the line of the Lyman group for the hydrogen spectrum is

Positronium consists of a bound state of an electron and a positron.A positron is exactly the same as an electron,except it has a charge of +e instead of -e.In the classical model,both particles orbit a point midway between them.The reduced mass of positronium is equal to

The Bohr model of hydrogen is based on the quantization of

The minimum orbital angular momentum quantum number for the is

The frequency of the line of the Balmer group for the hydrogen spectrum is

The electron in a singly ionized helium atom,which consists of two protons,two neutrons and only one electron,makes a transition from the n = 2 state to the n = 1 state,emitting a single photon in the process.What is the energy of this photon?

An electron in the hydrogen atom makes a transition from the state to an nth state.The electron gains 0.50 eV of energy.What value of is the final state of the electron?

The period of rotation of electron on the second Bohr orbit is

The maximum orbital angular momentum quantum number for the is

In the Bohr model of hydrogen,as the principle quantum number n increases,

The energy contained in a length of a 3.00-mW laser beam in vacuum is 1.80 * 10^-10 J.What is the length of the beam?

The energy contained in laser beam of length 2.00 m that moves through vacuum is 1.80 * 10^-10 J.What is the power of the laser?