2.7 Photons Flashcards
1
Q
Photoelectric effect
A
When light or ultraviolet radiation of short enough wavelength falls on a surface, electrons are emitted from the surface.
2
Q
Work function, φ
A
The work function of a surface is the minimum energy needed to remove an electron from the surface. Unit: J or eV
3
Q
Electron volt (eV)
A
This is the energy transferred when an electron moves between two points with a potential difference of 1 V between them. 1 eV = 1.60 × 10-19 J
So for an electron being accelerated it is the kinetic energy acquired when accelerated through a pd of 1 V.
4
Q
Ionisation
A
The removal of one or more electrons from an atom.
5
Q
Ionisation energy
A
the minimum energy needed to remove an electron from the atom in its ground state. Unit: J
