A section of the emission spectrum of a mercury lamp is shown - HSC - SSCE Chemistry - Question 20 - 2016 - Paper 1

In atomic absorption spectroscopy (AAS), the correct pair of intensities is crucial for accurately measuring the amount of mercury present in the sample. The first intensity should correspond to the emission wavelength of the mercury lamp, and the second intensity should relate to the detection wavelength that aligns with the absorbed light by mercury.

Based on the candidates:

• Option (A) uses $I(615.2 ext{ nm})$ and $I_d(615.2 ext{ nm})$, focusing on the same wavelength. This is valid as it allows for direct detection of emission and absorption at that specific wavelength.

• Options (B), (C), and (D) either mix wavelengths from different light emissions or do not correctly relate to the measurement process.

Thus, the correct answer is (A): $I(615.2 ext{ nm})$ and $I_d(615.2 ext{ nm})$.