Rhodium (Rh) – Periodic Table (Element Information & More)

This is a SUPER easy guide on Rhodium element.

In fact, the table mentioned below is the perfect information box (Which gives you every single detail about the Rhodium element in Periodic table.)

So if you want to know anything about Rhodium element, then this guide is for you.

Let’s finish this very quickly.

Rhodium Element (Rh) Information

Appearance	Silvery white metallic luster
State (at STP)	Solid
Position in Periodic table	Group: 9, Period: 5, Block: d
Category	Transition metals
Atomic number or  Protons	45
Neutrons	58
Electrons	45
Symbol	Rh
Atomic mass	102.91 u
Electrons arrangement or  Bohr model	2, 8, 18, 16, 1
Electronic configuration	[Kr] 4d8 5s1
Atomic radius	195 picometers (van der Waals radius)
1st Ionization energy	7.459 eV
Electronegativity	2.28 (Pauling scale)
Crystal structure	FCC (Face centered cubic)
Melting point	2237 K or 1964 °C or 3567 °F
Boiling point	3968 K or 3695 °C or 6683 °F
Density	12.45 g/cm3
Main isotope	103Rh
Who discovered Rhodium and when?	William Hyde Wollaston in 1804
CAS number	7440-16-6

Rhodium in Periodic table

Rhodium element is in group 9 and period 5 of the Periodic table. Rhodium is the d-block element and it belongs to transition metals group.

Click on above elements (in Periodic table) to see their information or Visit Interactive Periodic Table (which shows names, symbol, atomic mass, electron configuration, electrons arrangement, etc. of all the elements)

Click on above elements (in Periodic table) to see their information

←Move to: Ruthenium (Ru) element – Periodic Table
→Move to: Palladium (Pd) element – Periodic Table

Why is Rhodium in Period 5?

Let me ask you a question.

How many shells does Rhodium have?

It’s 5. Right? 

You have already seen the bohr model of rhodium atom in the above table.

From the Bohr model, it can be found that the number of orbits or shells in rhodium is 5. Hence, as rhodium has 5 orbits, it lies in period 5 of the Periodic table. 

Why is Rhodium in d-block?

Before knowing this reason, first of all I want to ask you a simple question.

How can you determine the blocks-wise position of elements?

The simple answer: The elements will lie in the s, p, d or f block will completely depend upon the subshell in which the last electron will enter.

For example; the electron configuration of rhodium is [Kr] 5s¹ 4d⁸. 

So the last electron of rhodium enters the d-subshell or d-orbital. 

Hence, rhodium is the d-block element.

Is Rhodium a Transition Metal? Why?

Yes, Rhodium is a transition metal because it has incompletely filled d-orbital in its ground state.

Let me explain the exact meaning of this.

According to the definition of transition metals;
The element should compulsorily have incomplete d-orbitals, either in their ground state (M) or most common oxidation states (M¹⁺, M²⁺, etc) then only they are called transition metals.

Now, the ground state of Rhodium means its normal state in which it has neither gained nor lost any electron/s.

So the ground state of Rhodium is Rh.

And the ground state electronic configuration of Rhodium is [Kr] 5s¹ 4d⁸.

In this state, if we see the electron configuration of Rhodium, then it possesses incomplete d-orbitals.

Because, there are only eight electrons in the d-orbitals. 

In order to have the complete d-orbitals, there must be 10 electrons in it.

But in the ground state electronic configuration of rhodium, you can see that it has only 8 electrons in d-orbitals.

Thus, Rhodium has incomplete d-orbitals.

And hence, as Rhodium has incomplete d-orbitals, it is considered as a transition metal.

5 Interesting facts about Rhodium

Interesting facts about rhodium element are mentioned below.

1. The name rhodium was derived from the Greek word “Rhodon” which means rose.
2. Rhodium is a very rare metal and its proportion in earth’s crust is only 1 part per 200 million. [1]
3. Rhodium was discovered by William Hyde Wollaston in 1804. He was also the person behind the discovery of palladium.
4. Out of the total available rhodium, around 87% of rhodium is used in catalytic converters.
5. Rhodium is a very rare metal and it can be obtained from the waste product of uranium fission.

Properties of Rhodium

The physical and chemical properties of rhodium element are mentioned below.

Physical properties of Rhodium

Physical properties of rhodium are mentioned below.

• Rhodium is a solid metal having silvery white metallic luster.
• Rhodium is a hard reflective metal and it is resistant to wear.
• The melting point of rhodium is 1964 °C and its boiling point is 3695 °C.
• The atomic mass of rhodium is 102.91 u and its density is 12.45 g/cm³.
• The crystal structure of rhodium is FCC (Face centered cubic).
• Rhodium has a stable isotope (¹⁰³Ru) which has an abundance of almost 100%. Besides this, there are many other radioactive isotopes of rhodium.

Chemical properties of Rhodium

Chemical properties of rhodium are mentioned below.

• Rhodium is a transition metal and it has incomplete d-subshells.
• Rhodium is a corrosive resistant metal.
• Rhodium does not react with oxygen easily and hence it is also known as a noble metal.
• Rhodium does not show any chemical reaction with air and water upto 600 °C temperature.
• Rhodium is also chemically very less reactive to most of the acids.

Uses of Rhodium

Uses of rhodium are mentioned below.

• Rhodium is an element which is used in catalytic converters that are used in cleaning the vehicle emissions.
• Rhodium is also used as a catalyst in chemical industries to prepare nitric acid as well as acetic acid.
• Rhodium is also used in coating of optical fibers as well as coating of crucibles.
• Rhodium is basically used as an alloying metal with platinum and iridium which provides resistance against higher temperatures.

Explore our New Interactive Periodic Table (with Rotating Bohr Models and More)

Details about this Periodic table:

• Access detailed info on all elements: atomic mass, electron configurations, charges, and more.
• View rotating Bohr models for all 118 elements.
• Get a free HD image of the Periodic Table.

Note: For future use, bookmark this Periodic table or visit “PeriodicTableGuide.com”

External resources:

1. Rhodium – Element information, properties and uses | Periodic Table. (n.d.). Rhodium – Element Information, Properties and Uses | Periodic Table. https://www.rsc.org/periodic-table/element/45/rhodium
2. Rhodium – Wikipedia. (2007, December 10). Rhodium – Wikipedia. https://en.wikipedia.org/wiki/Rhodium
3. P. (n.d.). Rhodium | Rh (Element) – PubChem. Rhodium | Rh (Element) – PubChem. https://pubchem.ncbi.nlm.nih.gov/element/Rhodium
4. It’s Elemental – The Element Rhodium. (n.d.). It’s Elemental – the Element Rhodium. https://education.jlab.org/itselemental/ele045.html
5. Rhodium (Rh) | AMERICAN ELEMENTS ® (n.d.). American Elements: The Materials Science Company. https://www.americanelements.com/rh.html