Anickel crystal's work function is measured to be 5.22 ev at 25°c. as the temperature increases by 300°c, the work function drops by 50 mev.

by how much does this shift the threshold wavelength for photoelectric emission?

The shift the threshold wavelength for photoelectric emission is 2.317 nm.

Explanation:

Given that,

Work function = 5.22 eV

Temperature = 25°C

Increased temperature = 300°C

Drop work function = 50 meV

We need to calculate the shift the threshold wavelength for photoelectric emission

Using formula of work function

The wavelength for initial temperature,

The wavelength for final temperature,

The change in wavelength is

Put the value into the formula

Hence, The shift the threshold wavelength for photoelectric emission is 2.317 nm.

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

the answer would be c. motion and direction

i hope this : )