Explanation: energy levels are three(counting number of cyecles) outer electrons are 3 also
Answer:3,3
<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>
Fluorine(F)
Explanation:-
- Fluorine has Z=9
- +2 charge means 2 electrons donated (7left only)
Lets look at Electronic configuration

Answer:
elements in same group have same valence electron.
period of element is equal to valence shell
Explanation:
if the elements are in a same group then they will be having same number of valence electron.
the period of an element in periodic table is equal to the valence shell of the element. that is if the valence electron are in 3 rd shell then the element will be in third period.
Answer:
they are indeed very strong