Question 1
Calculate the wavelength (in nm) of the red light emitted by a neon sign with a frequency of 4.74 x 1014 Hz.
A)
704 nm
B)
158 nm
C)
466 nm
D)
633 nm
E)
142 nm
My answer: D.633 nm
Question 2
How many photons are contained in a burst of yellow light (589 nm) from a sodium lamp that contains 609 kJ of energy?
A)
4.03 x 1028 photons
B)
3.06 x 1030 photons
C)
1.80 x 1024 photons
D)
3.37 x 1019 photons
My answer: C. 1.80 x 10^24 photons (ignore the incorrect ..1024..I meant 10^24)
Question 3
Determine the shortest frequency of light required to remove an electron from a sample of Ti metal, if the binding energy of titanium is 3.14 x 103 kJ/mol.
A)
4.74 x 1015 Hz
B)
6.19 x 1015 Hz
C)
1.27 x 1015 Hz
D)
7.87 x 1015 Hz
E)
2.11 x 1015 Hz
My answer : D 7.87 x 10^15 Hz (again.. ignore the incorrect typing of the exponent)
Question 4
Determine the energy change associated with the transition from n=2 t n=5 in the hydrogen atom.
A)
-2.18 x 10-19 J
B)
6.54 x 10-19 J
C)
4.58 x 10-19 J
D)
-1.53 x 10-19 J
E)
2.18 x 10-19 J
My answer: C 4.58 x 10^/19 J
Question 5
What are the possible values of l if n=6?
A)
-4, -3, -2, -1, 0, +1, +2, +3, +4
B)
-5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5
C)
0, 1, 2, 3, 4, or 5
D)
6
My answer: C 0,1,2,3,4, or 5
#5. "ell" may vary from zero to n-1 in whole numbers.
#1, 2, 4 are right.
Looks like you did a great job with your answers! All of them are correct.
Question 1: The correct answer is D) 633 nm. You correctly calculated the wavelength using the formula λ = c/v, where λ is the wavelength, c is the speed of light, and v is the frequency.
Question 2: The correct answer is C) 1.80 x 10^24 photons. You correctly used the formula E = hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength, to calculate the number of photons.
Question 3: The correct answer is D) 7.87 x 10^15 Hz. You correctly used the formula E = hv, where E is the binding energy, h is Planck's constant, and v is the frequency, to calculate the required frequency of light.
Question 4: The correct answer is C) 4.58 x 10^-19 J. You correctly used the formula ΔE = -2.18 x 10^-18 J (1/nf^2 - 1/ni^2), where ΔE is the energy change, nf is the final energy level, and ni is the initial energy level, to calculate the energy change.
Question 5: The correct answer is C) 0, 1, 2, 3, 4, or 5. You correctly identified the possible values of the angular momentum quantum number (l) for a given principal quantum number (n) using the rule l = 0, 1, 2, ..., n-1.
Great job!
For Question 1: To calculate the wavelength, you need to use the formula: wavelength = speed of light / frequency. The speed of light is a constant value of 3.00 x 10^8 m/s. Convert the frequency to Hz by multiplying it by 10^14 (since it is given in Hz), then substitute the values into the formula. The correct answer is D) 633 nm.
For Question 2: To calculate the number of photons, you need to use the formula: energy = number of photons x energy per photon. The energy per photon can be calculated using the formula: energy per photon = (Planck's constant x speed of light) / wavelength. Convert the wavelength to meters and substitute the values into the formula. The correct answer is C) 1.80 x 10^24 photons.
For Question 3: To determine the frequency required to remove an electron, you need to use the formula: frequency = binding energy / Planck's constant. Convert the binding energy to J/mol by multiplying it by 10^3 (since it is given in kJ/mol), then substitute the values into the formula. The correct answer is D) 7.87 x 10^15 Hz.
For Question 4: To determine the energy change, you need to use the formula: energy change = (-2.18 x 10^-18 J) / (n2^2 - n1^2), where n2 is the final energy level and n1 is the initial energy level. Substitute the values into the formula. The correct answer is C) 4.58 x 10^-19 J.
For Question 5: The possible values of l represent the different orbital shapes. For a given value of n, the possible values of l range from 0 to (n-1). Therefore, the correct answer is C) 0, 1, 2, 3, 4, or 5.