Calculate the molecular weights for NH, and SF. NH, =
g/mol
SF, =
How many grams of NH, are needed to provide the same number of molecules as in 0.95 g of SF.?
mass of NH3:
g

Here's what I get  

Explanation:

a. Time scales

Phosphorescence               10     s to 10⁻⁴  s

Fluorescence                       10⁻⁷  s to 10⁻¹⁰ s

Intersystem crossing           10⁻⁸  s to 10⁻¹⁰ s

Vibrational energy transfer 10⁻¹⁰ s to 10⁻¹² s

Absorption                           10⁻¹⁵ s

The first Jablonski diagram below shows the time scales for the different processes.

b. Fluorescence vs. phosphorescence

In fluorescence, a quantum of light excites an electron to an excited singlet state (S₁).

It quickly drops back to the ground state singlet (S₀) and emits a quantum of light.

In phosphorescence. the electron moves by intersystem crossing to an excited triplet state (T₁) and then drops to S₀.

According to quantum transition rules, intersystem crossing from S₁ to T₁ and dropping from T₁ to S₀ are rather unlikely.

Thus, phosphorescence times can range from milliseconds to tens of seconds.

The second Jablonski diagram shows fluorescence and phosphorescence in more detail.