How to find electronic configuration of an element ?
Follow the steps below to write short cut version of electron configurations.
Step 1: Find the element on the periodic table.
Step 2: Go back to the last noble gas that was passed (atomic number).
Step 3: Write the symbol of the noble gas in brackets to start your electron configuration. Put the atomic number of the noble gas beneath the symbol to let you know the number of electrons already represented. Take note of the row the noble gas is in on the periodic table.
Step 4: Continue your electron configuration using the row after the noble gas. For example, Krypton ends the 4th row so you would begin with 5. Always begin with the s subshell.
Step 5: Continue writing your electron configuration following the chart until you reach the correct number of electrons.
Example: Write the short cut electron configuration for osmium.
Description Example Step 1: Find the element on the periodic table. Step 1: Osmium is element 76. Step 2: Go back to the last noble gas that was passed (atomic number). Step 2: Going back, the last noble gas was xenon. Step 3: Write the symbol of the noble gas in brackets to start your electron configuration. Put the atomic number of the noble gas beneath the symbol to let you know the number of electrons already represented. Take note of the row the noble gas is in on the periodic table. Step 3: Os: [Xe]
54
Xenon ends the fifth row on the periodic table.
Step 4: Continue your electron configuration using the row after the noble gas. For example, Krypton ends the 4th row so you would begin with 5. Always begin with the s subshell. Since xenon ends the fifth row of the periodic table, we should begin with the sixth.
Step 4:Os: [Xe] 6s
54
Step 5: Continue writing your electron configuration following the chart until you reach the correct number of electrons. Since osmium is 76, we must represent 76 electrons.
Step 5: Os: [Xe] 6s2 4f14 5d6
54
Follow the steps below to write short cut version of electron configurations.
Step 1: Find the element on the periodic table.
Step 2: Go back to the last noble gas that was passed (atomic number).
Step 3: Write the symbol of the noble gas in brackets to start your electron configuration. Put the atomic number of the noble gas beneath the symbol to let you know the number of electrons already represented. Take note of the row the noble gas is in on the periodic table.
Step 4: Continue your electron configuration using the row after the noble gas. For example, Krypton ends the 4th row so you would begin with 5. Always begin with the s subshell.
Step 5: Continue writing your electron configuration following the chart until you reach the correct number of electrons.
Example: Write the short cut electron configuration for osmium.
| Description | Example |
| Step 1: Find the element on the periodic table. | Step 1: Osmium is element 76. |
| Step 2: Go back to the last noble gas that was passed (atomic number). | Step 2: Going back, the last noble gas was xenon. |
| Step 3: Write the symbol of the noble gas in brackets to start your electron configuration. Put the atomic number of the noble gas beneath the symbol to let you know the number of electrons already represented. Take note of the row the noble gas is in on the periodic table. | Step 3: Os: [Xe] Xenon ends the fifth row on the periodic table. |
| Step 4: Continue your electron configuration using the row after the noble gas. For example, Krypton ends the 4th row so you would begin with 5. Always begin with the s subshell. | Since xenon ends the fifth row of the periodic table, we should begin with the sixth. Step 4:Os: [Xe] 6s |
| Step 5: Continue writing your electron configuration following the chart until you reach the correct number of electrons. | Since osmium is 76, we must represent 76 electrons. Step 5: Os: [Xe] 6s2 4f14 5d6 |
