Elements·Plutonium
94
Pu
Plutonium
244

Plutonium

Actinide

Plutonium is element 94, symbol Pu. It sits in period 7, in the rows below the table, and weighs 244.

The second row below the table. All radioactive, and most of them made by people.

Atomic number
94
Atomic weight
244
Period
Period 7
Group
set below the table
Block
f block
Electron configuration
[Rn] 7s2 5f6
Neutrons
150

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 Plutonium's number and symbol?

Element 94, symbol Pu, atomic weight 244.

Q. Where does it sit in the table?

Period 7, among the actinides drawn below the table.

Q. What is its electron configuration?

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f6, or [Rn] 7s2 5f6 for short.

Q. How many neutrons does it have?

Rounding the atomic weight and subtracting the atomic number gives 150. The exact count depends on the isotope.