Introduction to Chemistry: Structures and Solutions Week 1 Exercises Quiz Answers

Introduction to Chemistry: Structures and Solutions 

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Week 1 Exercises Quiz Answers

Question 1)

What is the frequency of a photon with a wavelength of 781 nm. Report your answers to three significant digits.

The frequency is = _________ s-1

Answers: 

Question 2)

What is the energy of a photon with a wavelength of 260 nm. Report your answers to three significant digits.  

The energy is _________ J.

Answers: 

Question 3)

Which electron transition in a hydrogen atom would absorb the photon of greatest frequency?

• n = 3 to n = 1
• n= 12 to n= 6
• n = 1 to n= 4
• n = 35 to n = 2
• n = 2 to n= 9
• n = 6 to n = 2

Question 3)

Which electron transition in a hydrogen atom would emit the photon of greatest frequency?

• n= 12 to n= 6
• n = 35 to n = 2
• n = 1 to n = 4
• n = 2 to n= 9
• n = 3 to n= 1
• n = 6 to n = 2

Question 4)

Below is the energy level diagram (not drawn to scale) representing the transitions made by an electron in a hydrogen atom that result in the observed lines of both the absorption and emission spectra. Some are in the visible region, and some are not.

4 different energy photons are represented (approximate wavelengths are given in parentheses):

infrared (~ 10e-4 m)

red (~ 10e-6 m)

blue (~ 10e-7 m)

ultraviolet (~ 10e-8 m)

Match the transition (a - h) with the photon described (approximate wavelengths are given in parentheses.) Your answer input should be a single, lower case letter.

(Please note: This is not a problem for which a calculator is required. Your knowledge of the Bohr model of the atom and the relative energies of transitions is all that is needed.)

Smallest energy emission

Answers: 

Question 5)

List the types of electromagnetic radiation with frequencies higher than visible light. (Select all that apply.)

• x-rays
• ultraviolet light
• radio waves  
• gamma rays

Question 6)

Two of the emission wavelengths in the hydrogen emission spectrum are 656 nm and 486 nm. One of these is due to the electron’s n= 4 to n = 2 transition, and the other is due to the electron’s n = 3 to n = 2 transition. Which wavelength goes with which transition?

The n = 3 to n = 2 transition produces the ________.

• 656 nm emission line
• 486 nm emission line

Question 7)

Which element burns with a characteristic bright red flame?  

• strontium
• copper
• boron
• potassium
• sodium

Question 8)

Select the correct words to fill in the blanks:

In the Bohr model of the hydrogen atom, the n=5 to n=2 electronic transition corresponds with an ______ of energy; the change in the energy of the atom in this process is a _______ value.

• absorption, positive
• emission, negative
• absorption, negative
• emission, positive

Question 5)

List the types of electromagnetic radiation with frequencies lower than x-rays. (Please select all that apply.)

• infrared light  
• microwaves
• gamma rays
• visible light

Question 7)

Which elements burn with a characteristic green flame? Please select all that apply

• sodium
• potassium
• strontium
• copper(II)
• boron

Question 8

Select the correct words to fill in the blanks:

In the Bohr model of the hydrogen atom, the n=1 to n=4 electronic transition corresponds with an ______ of energy; the change in the energy of the atom in this process is a _______ value.

• absorption, positive
• emission, positive
• absorption, negative
• emission, negative

Question 7)

Which element burns with a characteristic lavender (light purple) flame?  

• potassium
• strontium
• copper
• boron
• sodium

Question 5)

List the types of electromagnetic radiation with frequencies lower than visible light. (Select all that apply.)

• ultraviolet light
• radio waves   
• gamma rays
• x-rays