The work function of a metal is ` 2.5 xx 10^-19 J`. (a) Find the threshold frequency for photoelectric emission. (b) If the metal is exposed to a light beam of frequency `6.0 xx 10^14` Hz, what will be the stopping potential ?

Explanation

To solve the given problem, we will break it down into two parts as stated in the question.

### Part (a): Finding the Threshold Frequency

1. **Understanding the Work Function**:
The work function (φ) of a metal is the minimum energy required to remove an electron from the surface of the metal. The relationship between the work function and the threshold frequency (ν₀) is given by the equation:
\[
φ = hν₀
...