The following metals could be used in the photovoltaic cell described above (mark all that could be used): Choose one or more:
O potassium ( = 3.78 × 10⁻¹⁹J)
O silver ( = 7.59 × 10⁻¹⁹J)
O silicon ( = 7.24 x 10⁻¹⁹J)
O titanium ( = 6.94 × 10 ¹⁹J) %3D
O tungsten ( = 7.20 × 10⁻¹⁹J)
O barium ( = 4.29 × 10⁻¹⁹J)