Answer:
Frequency
Explanation:
Photons are the packet of energy. They are massless and chargeless particles. They travel in the vacuum with the speed of light. The energy of photon is given by :

Where
h = Planck's constant
= frequency of photon
Or 
c = speed of light
= wavelength of photon
From the above equation, it is clear that the energy of photon is directly proportional to its frequency.
Answer:
6.6 N
Explanation:
Let's take the direction of the force of 4.0 N as positive x-direction. This means that the force of 3.0 N is at 40 degrees above it. So the components of the two forces along the x- and y-directions are:


So the resultant has components

So the magnitude of the resultant is

And in order for the body to be balanced, the third force must be equal and opposite (in direction) to this force: so, the magnitude of the third force must be 6.6 N.
Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.
Explanation:
False
electron and proton attract each other
Answer:
all of above I think sorry if I'm not right but I tried