I think it’s oxygen and carbon
<span>Photoelectric effect refer to the emission of electron or free carriers when light shine into a material. According to the Rutherford model, light of any energy should be able to make electrons leave the atom and be emitted.
The energy of the emitted electrons should be related to the intensity of the light. But the energy of the electron is actually only related to the energy of the light</span>
The first one would be it
c) nervous and endocrine system
Hope I helped! ( Smiles )
