Chemistry 8.1: Quantum Mechanics

8.1 - Quantum Mechanics

By Mrs. Ojerio

Multiple Choice

Sound travels through air at about 340 m/s. If a sound wave has a frequency of 260 Hz, what is its wavelength? (V = f $$\lambda$$ )

• $$\lambda\ =\ \frac{340}{260}$$

• $$\lambda\ =\ \frac{260}{340}$$

• $$\lambda\ =\ 340\times240$$

Multiple Choice

What is the velocity of a sound wave in helium with a frequency of 240 Hz and a wavelength of 4.0 m? (V = f $$\lambda$$ )

• $$V\ =\ \frac{240}{4.0}$$

• $$V\ =\ \frac{4.0}{240}$$

• $$V\ =\ 240\times4.0$$

Multiple Choice

Sound travels through air at about 340 m/s. If a sound wave has a wavelength of 0.05 m, what is its frequency? (V = f $$\lambda$$ )

• $$f\ =\ 340\times0.05$$

• $$f\ =\ \frac{340}{0.05}$$

• $$f\ =\ \frac{0.05}{340}$$

Multiple Choice

UV light has a wavelength of 200 nm. What is the frequency of this light? (c = f $$\lambda$$ )

Hint: $$200\ nm\ =\ 2\ x\ 10^{-7}\ m$$  and $$c\ =\ 3.00\ x\ 10^8\ \frac{m}{s}$$  

• $$f\ =\ \left(3.00\times10^8\right)\left(2\times10^{-7}\right)$$

• $$f\ =\ \frac{\left(2\times10^{-7}\right)}{\left(3.00\times10^8\right)}$$

• $$f\ =\ \frac{\left(3.00\times10^8\right)}{\left(2\times10^{-7}\right)}$$

Multiple Choice

A blue photon has the frequency $$6.7\ x\ 10^{14}\ Hz$$  . What is the energy of this photon? (E = hf)

Hint: $$h\ =\ 6.626\ x\ 10^{-34}\ J\cdot s$$  

• $$E=\left(6.626\times10^{-34}\right)\left(6.7\times10^{14}\right)$$

• $$E=\frac{\left(6.626\times10^{-34}\right)}{\left(6.7\times10^{14}\right)}$$

• $$E=\frac{\left(6.7\times10^{14}\right)}{\left(6.626\times10-34\right)}$$

Multiple Choice

What possible values of $$m_l$$  does the yellow highlighted electron have?

• 0

• 0, 1

• -1, 0, 1

• -2, -1, 0, 1, 2

Multiple Choice

Which is a possible set of quantum numbers for the arrow highlighted in yellow?

• n = 3, l = 0, ml = 0, ms = +1/2

• n = 3, l = 1, ml = -1, ms = +1/2

• n = 2, l = 0, ml = 0, ms = +1/2

• n = 3, l = 0, ml = -1, ms = +1/2