Question
Because spin–orbit coupling causes sodium to have two dominant and closely-spaced “D” examples of these features, sodium lamps only weakly distinguish objects of different colors. For 10 points each:
[10e] Hydrogen’s Balmer series is a set of what features?
ANSWER: spectral lines [or emission lines or absorption lines; prompt on D lines]
[10h] Sodium lamps’ D lines are often combined into a single center line at this wavelength, given in nanometers to the nearest integer. This is the standard wavelength of light used when measuring optical rotation.
ANSWER: 589 nanometers [or 589 nm; prompt on 590 nanometers or 590 nm by asking “what is the wavelength of the center line specifically?”]
[10m] A narrow spectrum helps sodium lamps achieve high efficiency, often reaching values of over 100 of these units per watt. Measurements in this flux unit, which equals one candela-steradian, are weighted according to the eye’s sensitivity to visible light.
ANSWER: lumens [or lm]
<Physics>
Summary
| 2024 ACF Nationals | 2024-04-21 | Y | 2 | 15.00 | 100% | 50% | 0% |
Data
| Berkeley A | Cornell A | 10 | 0 | 10 | 20 |
| Chicago A | Texas | 10 | 0 | 0 | 10 |