answers.input_text: short
answers.span_text: the minimum thermodynamic work ( i.e. energy ) needed to remove an electron from a solid to a point in the vacuum immediately outside the solid surface
questions: what is a work function of a metal
name: Work function
contexts: In solid - state physics , the work function ( sometimes spelled workfunction ) is the minimum thermodynamic work ( i.e. energy ) needed to remove an electron from a solid to a point in the vacuum immediately outside the solid surface . Here `` immediately '' means that the final electron position is far from the surface on the atomic scale , but still too close to the solid to be influenced by ambient electric fields in the vacuum . The work function is not a characteristic of a bulk material , but rather a property of the surface of the material ( depending on crystal face and contamination ) .