1)what are photo-electrons ?
2)an electron of mass 9.4 x 10^-31 kg accelerated through a potential difference,
attained a wavelength of 1.3 x 10-10 m. calculate its velocity.
[h= 6.6 x 10-34 js]

there are no correct statementd on the list of choices you provided.

6 cos 34, 6 sin 34 trig

falling water hydro = water .. spectcular places these plants are

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.