Hafnium (Hf)

Element 72 · transition metal · group 4, period 6

• 72 protons
• 2/4 valence e−
• +4
• d-block

Properties

Electron configuration of hafnium

Orbitals fill from the lowest energy upward. Writing that out for hafnium gives 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d² 6s², which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d2 6s2 in plain text.

Everything up to Xe is the same as in that noble gas, so it is usually abbreviated to [Xe] 4f¹⁴ 5d² 6s². The part outside the bracket is what does the chemistry.

Hafnium ion charge

Hafnium commonly forms ions with a charge of +4.

Common questions

How many valence electrons does hafnium have?

There is no single agreed answer for hafnium. Courses differ here. Counting only the outer s subshell gives 2; counting the inner d subshell with it gives 4, which is the group number. Check which convention your course uses before answering.

What is the electron configuration of hafnium?

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d2 6s2, or [Xe] 4f14 5d2 6s2 written from the previous noble gas. Orbitals fill lowest energy first.

What is the charge of hafnium?

Hafnium commonly forms ions with a charge of +4. Transition metals have several accessible oxidation states, which is why more than one charge is listed.

How many protons, electrons and neutrons does hafnium have?

A neutral hafnium atom has 72 protons and 72 electrons. Its standard atomic weight is 178.49, so the most common isotope has about 106 neutrons.

Nearby elements

• Zirconium (Zr)above it in group 4
• Rutherfordium (Rf)below it in group 4
• Lutetium (Lu)one place to its left
• Tantalum (Ta)one place to its right
• Titanium (Ti)same group, same valence count

See the ionic charge of every element →