The work function for metallic caesium is 2.14 ev. calculate the
kinetic energy and the speed of the electrons ejected by light of
wavelength
(a) 750 nm,
(b) 250 nm.

Part 1) No electrons are emitted

Part 2) Energy equals 2.837eV and velocity equals

Explanation:

From the basic equation of photoelectric effect we have

where

is the energy of the incident radiation

is the work function of the metal

is the kinetic energy of the emitted electrons

Thus applying values we get

1) for wavelength of 750 nanometers we have

The energy of incident radiation equals

Since the energy of incident radiation is lesser than the work function of the metal hence no electron's will be emitted.

Part 2)

Thus kinetic energy equals

Thus speed from energy is calculated as

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.