45 Rh Rhodium 102.905502

Rhodium

TRANSITION METAL
Bohr Model: Electrons arranged in energy shells around the nucleus.

Rhodium is a chemical element with symbol Rh and atomic number 45. It is a rare, silvery-white, hard, and chemically inert transition metal. It is a member of the platinum group.

Quick Facts

Atomic Number 45
Period 5
Group 9
Phase Solid
Appearance silvery white metallic
About Transition Metals

Transition metals are elements with partially filled d-orbitals. They are hard, have high melting points, and often form colored compounds.

History

Discovered By William Hyde Wollaston
Named By Unknown

Physical Properties

Atomic Mass 102.905502
Density 12.41 g/L
Molar Heat 24.98 J/(mol·K)
Phase Transition (Melting & Boiling Points)

Rhodium melts at 2237 K and boils at 3968 K.

Atomic Properties

Electron Config [Kr] 4d8 5s1
Electronegativity 2.28
Electron Affinity 110.27 kJ/mol
Ionization Energy 719.7 kJ/mol
Orbital Filling Diagram
This diagram visualizes electron configuration according to the Aufbau principle and Hund's rule. Boxes represent orbitals (s, p, d, f), while arrows indicate electrons with spin up or down. Electrons fill lower energy levels first and occupy orbitals singly before pairing.

Photograph

Image of Rhodium Source: Wikipedia

External Resources

Study Guide

Atomic Number

The number of protons in the nucleus, which defines the element.

Atomic Mass

The average mass of an atom, including protons and neutrons.

Electronegativity

A measure of how strongly an atom attracts electrons in a bond.

Ionization Energy

The energy required to remove an electron from an atom.

Electron Config

The arrangement of electrons in the atom's energy shells.