So is the idea that when light (the photons) is shined on an object, the electrons from that object get ejected? After reading up more on this effect, is it fair to say that this is due to the fact that the photons from the light source is providing energy to the electrons in the object, causing them to get excited and bounce off? Interestingly enough too, it seems like this is the exact idea used by solar panels; from sunlight, the photons bounce on the panels, and the excited electrons from the panels are then converted into current to be used as electricity.
zepluc
When I am using my camera, someone told me that some noises is caused by phisycal reasons.
I searched some of electronic noise types online, such as Thermal Noise, Read Noise and Amplification Noise. For amplification noise, when the camera increases the ISO in low-light environments to boost the signal, the amplification of the signal also amplifies the noise signals, leading to more visible noise in the images.
saif-m17
@ShonenMind You're correct that the photons provide energy to electrons. The interesting part about the photo-electric effect is that it proved that energy levels in atoms were quantized and that increasing the intensity of light below a certain wavelength wasn't enough to eject electrons. It was only when the wavelength was high enough and the individual photons carried enough energy that electrons were excited enough.
jananisriram
How do the photons approach the surface but electrons leave the surface?
michaelwiradharma
Would like to attempt to answer @jananisriram's question. Photons always carry a certain amount of energy from their electromagnetic radiation. Upon making contact with a surface, that energy needs to go somewhere, often displaced by the electrons. I think it's got less to do with repulsive forces and more about conservation of energy. The energy from the photons are certainly not enough to push out a photon from the atoms, as this would also result in some sort of nuclear reaction.
JunoLee128
It's interesting how before in this class we mainly thought of light as rays (particles) - and then in the color unit we considered wavelength (the wave); now we're cycling between these paradigms once again since the electrons have to show that light is quantized.
So is the idea that when light (the photons) is shined on an object, the electrons from that object get ejected? After reading up more on this effect, is it fair to say that this is due to the fact that the photons from the light source is providing energy to the electrons in the object, causing them to get excited and bounce off? Interestingly enough too, it seems like this is the exact idea used by solar panels; from sunlight, the photons bounce on the panels, and the excited electrons from the panels are then converted into current to be used as electricity.
When I am using my camera, someone told me that some noises is caused by phisycal reasons. I searched some of electronic noise types online, such as Thermal Noise, Read Noise and Amplification Noise. For amplification noise, when the camera increases the ISO in low-light environments to boost the signal, the amplification of the signal also amplifies the noise signals, leading to more visible noise in the images.
@ShonenMind You're correct that the photons provide energy to electrons. The interesting part about the photo-electric effect is that it proved that energy levels in atoms were quantized and that increasing the intensity of light below a certain wavelength wasn't enough to eject electrons. It was only when the wavelength was high enough and the individual photons carried enough energy that electrons were excited enough.
How do the photons approach the surface but electrons leave the surface?
Would like to attempt to answer @jananisriram's question. Photons always carry a certain amount of energy from their electromagnetic radiation. Upon making contact with a surface, that energy needs to go somewhere, often displaced by the electrons. I think it's got less to do with repulsive forces and more about conservation of energy. The energy from the photons are certainly not enough to push out a photon from the atoms, as this would also result in some sort of nuclear reaction.
It's interesting how before in this class we mainly thought of light as rays (particles) - and then in the color unit we considered wavelength (the wave); now we're cycling between these paradigms once again since the electrons have to show that light is quantized.