Answer:
See below
Explanation:
.75 = 1/2^(40/h)
log .75 / ( log 1/2) = 40 / h
<u>h = half life = 96.37683 min</u>
Answer is: (4) emits energy as it moves to a lower energy state.
Atom emits a characteristic set of discrete wavelengths, according to its electronic energy levels.
Emission spectrum of a chemical element is the spectrum of frequencies emitted due to an atom making a transition from a high energy state to a lower energy state.
Each transition has a specific energy difference.
Each element's emission spectrum is unique.
