Numerari from KnowledgeDoor---The scientific calculator with graphing, unit keypads, complex numbers, constants, advanced functions, user-defined keys, quick copy, and more! Learn more (Link leaves KnowledgeDoor website)

Element

Chemical Hardness

Click button to see citations

Aluminum

2.77 eV

Antimony

3.80 eV

Arsenic

4.5 eV 

Barium

2.9 eV 

Beryllium

4.5 eV 

Bismuth

3.74 eV

Boron

4.01 eV

Bromine

4.22 eV

Cadmium

4.66 eV

Calcium

4.0 eV 

Carbon

5.00 eV

Cesium

1.71 eV

Chlorine

4.68 eV

Chromium

3.06 eV

Cobalt

3.6 eV 

Copper

3.25 eV

Fluorine

7.01 eV

Gallium

2.9 eV 

Germanium

3.4 eV 

Gold

3.46 eV

Hafnium

3.0 eV 

Hydrogen

6.43 eV

Indium

2.8 eV 

Iodine

3.69 eV

Iridium

3.8 eV 

Iron

3.81 eV

Lanthanum

2.6 eV 

Lead

3.53 eV

Lithium

2.39 eV

Magnesium

3.90 eV

Manganese

3.72 eV

Mercury

5.54 eV

Molybdenum

3.1 eV 

Nickel

3.25 eV

Niobium

3.0 eV 

Nitrogen

7.23 eV

Osmium

3.8 eV 

Oxygen

6.08 eV

Palladium

3.89 eV

Phosphorus

4.88 eV

Platinum

3.5 eV 

Potassium

1.92 eV

Rhenium

3.87 eV

Rhodium

3.16 eV

Rubidium

1.85 eV

Ruthenium

3.0 eV 

Scandium

3.20 eV

Selenium

3.87 eV

Silicon

3.38 eV

Silver

3.14 eV

Sodium

2.30 eV

Strontium

3.7 eV 

Sulfur

4.14 eV

Tantalum

3.79 eV

Tellurium

3.52 eV

Thallium

2.9 eV 

Tin

3.05 eV

Titanium

3.37 eV

Tungsten

3.58 eV

Vanadium

3.1 eV 

Yttrium

3.19 eV

Zinc

4.94 eV

Zirconium

3.21 eV

Reference    (Click the button next to a value above to see complete citation information for that entry)

Pearson, Ralph G. "Absolute Electronegativity and Hardness: Application to Inorganic Chemistry." Inorganic Chemistry, volume 27, number 4, 1988, pp 734–740. doi:10.1021/ic00277a030

Heaven's Boulevard astronomical sky image for any location, date, and time. Personalize with a picture and message. Great gift for birthdays, anniversaries, or any special event. Learn more (Link leaves KnowledgeDoor website)