Answer:
1. 9.90 x 10^14 Hz
Explanation:
The work function is the minimum energy required to eject electron's from the surface of the metal. The frequency of photons that are capable of doing this is called the threshold frequency. Given the work function, the threshold frequency can be calculated in the following way
Work function = Planck's constant * frequency
6.56 x 10^-19 J = 6.62607004 × 10-34 m²-kg/s * f
f = 9.90 x 10^14 Hz
