Using the Rydberg equation, calculate the energy for the following electronic transitions in a hydrogen atom and label each as an absorption or an emission. When calculating, watch your signs! n = 3 → n = 1

a. Energy calculation
b. absorption or emission?

-1.94  * 10^-18 J

Since the electron moved from a higher to a lower energy level (n = 3 → n = 1) it is an emission.

Explanation:

From Rydberg equation;

E = -RH(1/n^2final - 1/n^2initial)

For a transition from  n = 3 → n = 1

RH = 2.18 * 10^-18 J

E = -(2.18 * 10^-18) (1/1^2 - (1/3^2)

E = -(2.18 * 10^-18) (1-1/9)

E= -(2.18 * 10^-18) (8/9)

E = -1.94  * 10^-18 J

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.