Question

The sodium falme testhas a characteristic yellow colour due to the emission of a vavelength of `589 nm ` What is the mass equivalent of one photon of this wavelength of this wavelength

Answer 1

According of de Broglie equation
`lambda = (h)/(mv)`
Wavelength of photon `= 589 nm = 589 xx 10^(-9)m `
Velocity of photon `= 3 xx 10^(8) m s^(-1)`
`m = (h)/(lambda v) = (6.626 xx 10^(-34) kg m^(2)s^(-1))/(589 xx 10^(-9) m xx 3 xx 10^(8) m s^(-1))`
`3.75 xx 10^(-34) kg`