Element

Work Function / eV

Aluminium

4.08

Beryllium

5

Cadmium

4.07

Calcium

2.9

Carbon

4.81

Caesium

2.1

Cobalt

5

Copper

4.7

Gold

5.1

Iron

4.5

Lead

4.14

Magnesium

3.68

Mercury

4.5

Nickel

5.01

Niobium

4.3

Potassium

2.3

Platinum

6.35

Selenium

5.11

Silver

4.73

Sodium

2.28

Uranium

3.6

Zinc

4.3