Physics homework help. QUESTION

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Complete these 15 questions by the end of the term. Unlike your

previous problem sets, you will have 5 attempts at each problem and

you will not be penalized for multiple submissions. Instead, your highest

score for each question part will be retained. This is being done because

detailed feedback is not available for these problems as it was on your

past assignments. However, “Read It” will be shown to you so you can

access the portion of the text pertaining to the problem, and when you

click on the answer box, you will also notice that your favorite “Practice

Another Version” button suddenly appears! When entering answers,

enter the numeric value accurate to three signi!cant !gures.

Assignment Submission & Scoring

Assignment Submission

For this assignment, you submit answers by

question parts. The number of submissions

remaining for each question part only changes

if you submit or change the answer.

Assignment Scoring

Your last submission is used for your score.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

–/3.5 –/3.6 –/3.6 –/3.6 –/7.1 –/7.1 –/7.1 –/7.1 –/36 –/3.5 –/3.5 –/3.6 –/3.6 –/3.5 –/3.6

Due Date

Instructions

Description

Module 9 – CH 10 and 11 HW – PHYS 102 January 2020 Online, section Wicker (0005), Spring 2020 | WebAssign 3/7/20, 11:09 PM

https://www.webassign.net/web/Student/Assignment-Responses/las…5814AD32ECAB73BECFC6ACE6F48F01E5B87A93B97FF&clear_user_cache=1 Page 3 of 8

Things around you are emitting infrared radiation that includes the wavelength 1.03 10 m. What is the energy of these IR

photons?

eV

Gamma rays (γ-rays) are high-energy photons. In a certain nuclear reaction, a γ-ray of energy 0.779 MeV (million electronvolts) is

produced. Compute the frequency of such a photon.

Hz

In a typical electron microscope, the momentum of each electron is about 1.3 10 kg-m/s. What is the de Broglie wavelength of

the electrons?

m

If a proton were traveling the same speed as electrons in a TV picture tube (about 7.0 10 m/s), what would its de Broglie

wavelength be? The mass of a proton is 1.67 10 kg.

m

-5

-22

7

-27

1. –/3.5 points OBINPHYS8 10.P.002. My Notes Ask Your Teacher

2. –/3.6 points OBINPHYS8 10.P.004. My Notes Ask Your Teacher

3. –/3.6 points OBINPHYS8 10.P.006. My Notes Ask Your Teacher

4. –/3.6 points OBINPHYS8 10.P.008. My Notes Ask Your Teacher

Module 9 – CH 10 and 11 HW – PHYS 102 January 2020 Online, section Wicker (0005), Spring 2020 | WebAssign 3/7/20, 11:09 PM

https://www.webassign.net/web/Student/Assignment-Responses/las…5814AD32ECAB73BECFC6ACE6F48F01E5B87A93B97FF&clear_user_cache=1 Page 4 of 8

(a) A hydrogen atom has its electron in the level. The radius of the electron’s orbit in the Bohr model is 1.905 nm. Find the de

Broglie wavelength of the electron under these circumstances.

m

(b) What is the momentum, mv, of the electron in its orbit?

kg-m/s

A hydrogen atom has its electron in the state.

(a) How much energy would have to be absorbed by the atom for it to become ionized from this level?

eV

(b) What is the frequency of the photon that could produce this result?

Hz

A hydrogen atom initially in the n = 2 level emits a photon and ends up in the ground state.

(a) What is the energy of the emitted photon?

eV

(b) If this atom then absorbs a second photon and returns to the n = 2 state, what must the energy of this photon be?

eV

n = 6

n = 3

5. –/7.1 points OBINPHYS8 10.P.009. My Notes Ask Your Teacher

6. –/7.1 points OBINPHYS8 10.P.011. My Notes Ask Your Teacher

7. –/7.1 points OBINPHYS8 10.P.012. My Notes Ask Your Teacher

Module 9 – CH 10 and 11 HW – PHYS 102 January 2020 Online, section Wicker (0005), Spring 2020 | WebAssign 3/7/20, 11:09 PM

https://www.webassign.net/web/Student/Assignment-Responses/las…5814AD32ECAB73BECFC6ACE6F48F01E5B87A93B97FF&clear_user_cache=1 Page 5 of 8

A neutral aluminum atom is in its ground state electronic configuration. How many of its electrons are in the n = 3 level?

electrons

Explain how you arrived at your answer.

The n = 1 level contains 8 electrons, the n = 2 level contains 2 electrons, and the n = 3 level contains 4 electrons.

The n = 1 level contains 2 electrons, the n = 2 level contains 8 electrons, and the n = 3 level contains 3 electrons.

The n = 1 level contains 1 electron, the n = 2 level contains 6 electrons, and the n = 3 level contains 6 electrons.

The n = 1 level contains 1 electron, the n = 2 level contains 8 electrons, and the n = 3 level contains 4 electrons.

The n = 1 level contains 2 electrons, the n = 2 level contains 8 electrons, and the n = 3 level contains 5 electrons.

Determine the nuclear composition (number of protons and neutrons) of the following isotopes.

(a) iron-56

protons

neutrons

(b) nickel-58

protons

neutrons

(c) antimony-121

protons

neutrons

(d) erbium-166

protons

neutrons

(e) uranium-238

protons

neutrons

(Z = 13)

8. –/7.1 points OBINPHYS8 10.P.014. My Notes Ask Your Teacher

9. –/36 points OBINPHYS8 11.P.001. My Notes Ask Your Teacher

Module 9 – CH 10 and 11 HW – PHYS 102 January 2020 Online, section Wicker (0005), Spring 2020 | WebAssign 3/7/20, 11:09 PM

https://www.webassign.net/web/Student/Assignment-Responses/las…5814AD32ECAB73BECFC6ACE6F48F01E5B87A93B97FF&clear_user_cache=1 Page 6 of 8

The isotope lithium-8 undergoes beta decay. Write the reaction equation and determine the identity of the daughter nucleus.

The isotope astatine-201 undergoes alpha decay. Write the reaction equation and determine the identity of the daughter nucleus.

Li → Be + e

8

3

9

4

−1

Li → Be + e

8

3

8

4

−1

Li → He + e

8

3

7

2

−1

Li → Be + e

8

3

7

4

−1

Li → He + e

8

3

8

2

−1

At → Fr + He 201

85

197

87

4

2

At → Bi + He 201

85

197

83

4

2

At → Bi + He 201

85

199

83

4

2

At → Fr + He 201

85

205

87

4

2

At → Bi + He 201

85

205

83

4

2

10. –/3.5 points OBINPHYS8 11.P.002. My Notes Ask Your Teacher

11. –/3.5 points OBINPHYS8 11.P.005. My Notes Ask Your Teacher

Module 9 – CH 10 and 11 HW – PHYS 102 January 2020 Online, section Wicker (0005), Spring 2020 | WebAssign 3/7/20, 11:09 PM

https://www.webassign.net/web/Student/Assignment-Responses/las…5814AD32ECAB73BECFC6ACE6F48F01E5B87A93B97FF&clear_user_cache=1 Page 7 of 8

The isotope palladium-120* undergoes gamma decay. Write the reaction equation, and determine the identity of the daughter

nucleus.

A Geiger counter registers a count rate of 5,200 counts per minute from a sample of a radioisotope. Six minutes later, the count rate

is 1,300 counts per minute. What is the half-life of the radioisotope?

min

An accident in a laboratory results in a room being contaminated by a radioisotope with a half-life of 4 days. If the radiation is

measured to be eight times the maximum permissible level, how much time must elapse before the room is safe to enter?

days

Pd* → Rh + γ

120

46

120

45

Pd* → Pd + γ

120

46

120

46

Pd* → Ag + γ

120

46

120

47

Pd* → Pd + γ

120

46

121

46

Pd* → Ag + γ

120

46

121

47

12. –/3.6 points OBINPHYS8 11.P.007. My Notes Ask Your Teacher

13. –/3.6 points OBINPHYS8 11.P.013. My Notes Ask Your Teacher

14. –/3.5 points OBINPHYS8 11.P.015. My Notes Ask Your Teacher

Module 9 – CH 10 and 11 HW – PHYS 102 January 2020 Online, section Wicker (0005), Spring 2020 | WebAssign 3/7/20, 11:09 PM

https://www.webassign.net/web/Student/Assignment-Responses/las…5814AD32ECAB73BECFC6ACE6F48F01E5B87A93B97FF&clear_user_cache=1 Page 8 of 8

When the plutonium bomb was tested in New Mexico in 1945, approximately 1 gram of matter was converted into energy. Suppose

another bomb is tested, and 5.4 grams of matter are converted into energy. How many joules of energy are released by the

explosion?

J