Elements·Ruthenium
44
Ru
Ruthenium
101.07

Ruthenium

Transition metal

Ruthenium is element 44, symbol Ru. It sits in period 5, group 8, and weighs 101.07.

Metals filling an inner shell as they go, giving several oxidation states and colour.

Atomic number
44
Atomic weight
101.07
Period
Period 5
Group
Group 8
Block
d block
Electron configuration
[Kr] 5s2 4d6
Neutrons
57

The periodic table

Rows are periods, columns are groups. Tap any square to open that element.

Others in the same group

Neighbours by number

How to read this

  • A row (period) is the number of electron shells. Elements in period 3 carry three of them.
  • A column (group) tells you how many electrons sit in the outer shell — which is why a group behaves alike.
  • Atomic weight runs at roughly twice the atomic number: about as many neutrons as protons.
  • The 28 lanthanides and actinides are drawn below the table. Slotting them in would stretch it to 32 columns.

Frequently asked questions

Q. What are Ruthenium's number and symbol?

Element 44, symbol Ru, atomic weight 101.07.

Q. Where does it sit in the table?

Period 5, group 8 — a transition metal.

Q. What is its electron configuration?

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d6, or [Kr] 5s2 4d6 for short.

Q. How many neutrons does it have?

Rounding the atomic weight and subtracting the atomic number gives 57. The exact count depends on the isotope.