# Complete Electron Configuration of Ruthenium (Ru, Ru3+)

Ruthenium is the 44th element in the periodic table and its symbol is ‘Ru’. In this article, I have discussed in detail how to easily write the complete electron configuration of ruthenium.

## What is the electron configuration of ruthenium?

The total number of electrons in ruthenium is forty-four. These electrons are arranged according to specific rules in different orbitals.

The arrangement of electrons in ruthenium in specific rules in different orbits and orbitals is called the electron configuration of ruthenium.

The electron configuration of ruthenium is [Kr] 4d^{7} 5s^{1}, if the electron arrangement is through orbitals. Electron configuration can be done in two ways.

- Electron configuration through orbit (Bohr principle)
- Electron configuration through orbital (Aufbau principle)

Electron configuration through orbitals follows different principles. For example Aufbau principle, Hund’s principle, and Pauli’s exclusion principle.

## Ruthenium atom electron configuration through orbit

Scientist Niels Bohr was the first to give an idea of the atom’s orbit. He provided a model of the atom in 1913. The complete idea of the orbit is given there.

The electrons of the atom revolve around the nucleus in a certain circular path. These circular paths are called orbit(shell). These orbits are expressed by n. [n = 1,2,3,4 . . . The serial number of the orbit]

K is the name of the first orbit, L is the second, M is the third, and N is the name of the fourth orbit. The electron holding capacity of each orbit is 2n^{2}.

Shell Number (n) | Shell Name | Electrons Holding Capacity (2n^{2}) |

1 | K | 2 |

2 | L | 8 |

3 | M | 18 |

4 | N | 32 |

For example,

- n = 1 for K orbit.

The maximum electron holding capacity in K orbit is 2n^{2}= 2 × 1^{2}= 2. - For L orbit, n = 2.

The maximum electron holding capacity in L orbit is 2n^{2}= 2 × 2^{2}= 8. - n=3 for M orbit.

The maximum electron holding capacity in M orbit is 2n^{2}= 2 × 3^{2 }= 18. - n=4 for N orbit.

The maximum electron holding capacity in N orbit is 2n^{2}= 2 × 4^{2}= 32.

Therefore, the maximum electron holding capacity in the first shell is two, the second shell is eight and the 3rd shell can have a maximum of eighteen electrons. The atomic number is the number of electrons in that element.

The atomic number of ruthenium is 44. That is, the number of electrons in ruthenium is forty-four. Therefore, a ruthenium atom will have two electrons in the first shell, eight in the 2nd orbit, and eighteen electrons in the 3rd shell.

According to Bohr’s formula, the fourth shell will have sixteen electrons but the fourth shell of ruthenium will have fifteen electrons and the remaining one electron will be in the fifth shell.

Therefore, the order of the number of electrons in each shell of the ruthenium atom is 2, 8, 18, 15, 1. Ruthenium shows exceptional electron configuration for equal energy orbitals. Electrons can be arranged correctly through orbits from elements 1 to 18.

The electron configuration of an element with an atomic number greater than 18 cannot be properly determined according to the Bohr atomic model. The electron configuration of all the elements can be done through the orbital diagram.

## Electron configuration of ruthenium through orbital

Atomic energy shells are subdivided into sub-energy levels. These sub-energy levels are also called orbital. The most probable region of electron rotation around the nucleus is called the orbital.

The sub-energy levels depend on the azimuthal quantum number. It is expressed by ‘l’. The value of ‘l’ is from 0 to (n – 1). The sub-energy levels are known as s, p, d, and f.

Orbit Number | Value of ‘l’ | Number of subshells | Number of orbital | Subshell name | Electrons holding capacity | Electron configuration |

1 | 0 | 1 | 1 | 1s | 2 | 1s^{2} |

2 | 0 1 | 2 | 1 3 | 2s 2p | 2 6 | 2s^{2} 2p^{6} |

3 | 0 1 2 | 3 | 1 3 5 | 3s 3p 3d | 2 6 10 | 3s^{2} 3p^{6} 3d^{10} |

4 | 0 1 2 3 | 4 | 1 3 5 7 | 4s 4p 4d 4f | 2 6 10 14 | 4s^{2} 4p^{6} 4d^{10} 4f^{14} |

For example,

- If n = 1,

(n – 1) = (1–1) = 0

Therefore, the value of ‘l’ is 0. So, the sub-energy level is 1s. - If n = 2,

(n – 1) = (2–1) = 1.

Therefore, the value of ‘l’ is 0, 1. So, the sub-energy levels are 2s, and 2p. - If n = 3,

(n – 1) = (3–1) = 2.

Therefore, the value of ‘l’ is 0, 1, 2. So, the sub-energy levels are 3s, 3p, and 3d. - If n = 4,

(n – 1) = (4–1) = 3

Therefore, the value of ‘l’ is 0, 1, 2, 3. So, the sub-energy levels are 4s, 4p, 4d, and 4f. - If n = 5,

(n – 1) = (n – 5) = 4.

Therefore, l = 0,1,2,3,4. The number of sub-shells will be 5 but 4s, 4p, 4d, and 4f in these four subshells it is possible to arrange the electrons of all the elements of the periodic table.

Subshell name | Name source | Value of ‘l’ | Value of ‘m’(0 to ± l) | Number of orbital (2l+1) | Electrons holding capacity2(2l+1) |

s | Sharp | 0 | 0 | 1 | 2 |

p | Principal | 1 | −1, 0, +1 | 3 | 6 |

d | Diffuse | 2 | −2, −1, 0, +1, +2 | 5 | 10 |

f | Fundamental | 3 | −3, −2, −1, 0, +1, +2, +3 | 7 | 14 |

The orbital number of the s-subshell is one, three in the p-subshell, five in the d-subshell and seven in the f-subshell. Each orbital can have a maximum of two electrons.

The sub-energy level ‘s’ can hold a maximum of two electrons, ‘p’ can hold a maximum of six electrons, ‘d’ can hold a maximum of ten electrons, and ‘f’ can hold a maximum of fourteen electrons.

Aufbau is a German word, which means building up. The main proponents of this principle are scientists Niels Bohr and Pauli. The Aufbau method is to do electron configuration through the sub-energy level.

The Aufbau principle is that the electrons present in the atom will first complete the lowest energy orbital and then gradually continue to complete the higher energy orbital.

The energy of an orbital is calculated from the value of the principal quantum number ‘n’ and the azimuthal quantum number ‘l’. The orbital for which the value of (n + l) is lower is the low energy orbital and the electron will enter that orbital first.

Orbital | Orbit (n) | Azimuthal quantum number (l) | Orbital energy (n + l) |

3d | 3 | 2 | 5 |

4s | 4 | 0 | 4 |

Here, the energy of 4s orbital is less than that of 3d. So, the electron will enter the 4s orbital first and enter the 3d orbital when the 4s orbital is full. The method of entering electrons into orbitals through the Aufbau principle is 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d.

The first two electrons of ruthenium enter the 1s orbital. The s-orbital can have a maximum of two electrons. Therefore, the next two electrons enter the 2s orbital. The p-orbital can have a maximum of six electrons.

So, the next six electrons enter the 2p orbital. The second orbit is now full. So, the remaining electrons will enter the third orbit. Then the two electrons will enter the 3s orbital and the next six electrons will be in the 3p orbital of the third orbit.

The 3p orbital is now full. So, the next two electrons will enter the 4s orbital and ten electrons will enter the 3d orbital. The 3d orbital is now full. So, the next six electrons enter the 4p orbital.

The 4p orbital is now full. Then next two electrons will enter the 5s orbital. But the values of the 4d & 5s orbitals of ruthenium are almost the same. Due to the fascination of electrons in the nucleus, one electron moves from 5s to 4d.

So next an electron will enter the 5s orbital and the remaining seven electrons enter the 4d orbital. Therefore, the ruthenium complete electron configuration will be 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{7} 5s^{1}. For this reason, ruthenium shows exceptional electron configuration.

Note:The unabbreviated electron configuration of ruthenium is [Kr] 4d^{7}5s^{1}. When writing an electron configuration, you have to write serially.

## Ruthenium ion(Ru^{3+}) electron configuration

The ground state electron configuration of ruthenium is 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{7} 5s^{1}.

This electron configuration shows that the last shell of ruthenium has an electron and the d-orbital has a total of seven electrons. Therefore, the valence electrons of ruthenium are eight.

The elements that have 1, 2, or 3 electrons in the last shell donate the electrons in the last shell during bond formation. The elements that form bonds by donating electrons are called cation.

The ruthenium atom donates an electron in the 5s orbital and two electrons in the 4d orbital to convert a ruthenium ion(Ru^{3+}).

Ru – 3e^{–} → Ru^{3+}

The electron configuration of ruthenium ion(Ru^{3+}) is 1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{5}.

This electron configuration shows that the ruthenium ion(Ru^{3+}) has four shells and the last shell has thirteen electrons. Ruthenium atom exhibits +3, +4 oxidation state. The oxidation state of the element changes depending on the bond formation.

## FAQs

### What is the symbol for ruthenium?

**Ans:**The symbol for ruthenium is ‘Ru’.### How many electrons does ruthenium have?

**Ans:**44 electrons.### How do you write the full electron configuration for ruthenium?

**Ans:**1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{7}5s^{1}.### How many valence electrons does ruthenium have?

**Ans:**Eight valence electrons. The last shell of ruthenium has an electron and the d-orbital has a total of seven electrons. Therefore, the valence electrons of ruthenium are eight.### What is the valency of ruthenium?

**Ans:**The valency of ruthenium is 3.### What is the noble gas core in the electron configuration for ru?

**Ans:**The noble gas core in the electron configuration for ru is [Kr] 4d^{7}5s^{1}. This configuration is also called abbreviated electron configuration.### What is the electron configuration for ru

^{3+}?**Ans:**The electron configuration of ruthenium ion(Ru^{3+}) is 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{5}.### How many different principal quantum numbers can be found in the ground state electron configuration of ruthenium?

**Ans:**In the electron configuration of ruthenium, there are five different principal quantum numbers: 1, 2, 3, 4, and 5. The electrons in the ground state of ruthenium occupy energy levels ranging from n = 1 to n = 5.### How many unpaired electrons are present in the ground state of the element ruthenium (ru)?

**Ans:**Four unpaired electrons. The d-sub shell has five orbital and each orbital can have a maximum of two electrons. In the ground state electron configuration of ruthenium, there are seven electrons occupy in the 4d orbital. So, the 4d orbital has three unpaired electrons and the 5s orbital has one unpaired electron.### How many principal energy levels are completely filled in atoms of ruthenium?

**Ans:**A total of three principal energy levels in a ruthenium atom are completely filled with electrons. They are 1st, 2nd, and 3rd energy levels. The order of the number of electrons in each shell of the ruthenium atom is 2, 8, 18, 15, 1.### When ruthenium (ru) forms a +2 cation, electrons are removed from which atomic orbital?

**Ans:**When ruthenium forms a +2 cation, the electron is removed from the 4d atomic orbital.### How many unpaired electrons does ruthenium have?

**Ans:**Four unpaired electrons. The d-sub shell has five orbital and each orbital can have a maximum of two electrons. In the electron configuration of ruthenium, there are seven electrons occupy in the 4d orbital. So, the 4d orbital has three unpaired electrons and the 5s orbital has one unpaired electron.### What’s the highest energy level of ruthenium’s electrons?

**Ans:**The 5th energy level is the highest energy level of ruthenium. The order of the number of electrons in each shell of the ruthenium atom is 2, 8, 18, 15, 1.### How many electrons can the 5th shell hold of ruthenium?

**Ans:**One electron. The values of the 4d & 5s orbitals of ruthenium are almost the same. Due to the fascination of electrons in the nucleus, one electron moves from 5s to 4d.### How many electrons can 3d orbital hold of ruthenium?

**Ans:**Ten electrons.### How many electrons are in the 4d orbital of ruthenium?

**Ans:**Seven electrons. The values of the 4d & 5s orbitals of ruthenium are almost the same. Due to the fascination of electrons in the nucleus, one electron moves from 5s to 4d.### How many electrons can the 3rd shell hold of ruthenium?

**Ans:**18 electrons. The formula of the electron holding capacity of each orbit is 2n^{2}. The maximum electron holding capacity in the 3rd orbit of ruthenium is 2n^{2}= 2 × 3^{2}= 18.