Rodio (Rh): Bohr Model, Protons, Neutrons & Electrons
Rodio is element number 45, a transition metal in group 9, period 5. Its atom has 45 protons, 58 neutrons and 45 electrons arranged in 5 shells: 2, 8, 18, 16, 1.
- 45 protons
- 58 neutrons
- 45 electrons
Protons, neutrons and electrons in rhodium
El atomic number of rhodium is 45, so every rhodium atom has 45 protons. A neutral atom has the same number of electrons, 45. The number of neutrons depends on the isotope: neutrons = mass number − atomic number. For rhodium-103, that is 103 − 45 = 58 neutrons.
How to draw the Bohr model of rhodium
- Draw the nucleus and write 45 p⁺ y 58 n⁰ inside it.
- Draw the first shell and put 2 electrons on it (the first shell holds at most 2).
- Draw the second shell and put 8 electrons on it.
- Draw the third shell and put 18 electrons on it.
- Draw the fourth shell and put 16 electrons on it.
- Draw the fifth shell and put 1 electron on it.
- Check: 2 + 8 + 18 + 16 + 1 = 45 electrons, the same as the number of protons.
From potassium onwards the shells don’t simply fill as 2, 8, 8: the fourth shell starts before the third is full, so the real arrangement above (2, 8, 18, 16, 1) is the one to draw.
Electron configuration
The electron configuration of rhodium is [Kr] 5s¹ 4d⁸. As a transition metal it fills an inner d-subshell, and its common ion is Rh³⁺.
Key facts about rhodium
| Symbol | Rh |
|---|---|
| Atomic number | 45 |
| Relative atomic mass | 102.91 |
| Group · period · block | group 9 · period 5 · d-block |
| Tipo | Metal de transición |
| State at 25 °C | solid |
| Capas electrónicas | 2, 8, 18, 16, 1 |
| Electron configuration | [Kr] 5s¹ 4d⁸ |
| Electrones de valencia | varies (outer shell: 1) |
| Common ion | Rh³⁺ |
| Electronegativity (Pauling) | 2.28 |
| First ionisation energy | 7.46 eV (720 kJ/mol) |
| Atomic radius (empirical) | 135 pm |
¿Dónde rhodium sits on the periodic table
Preguntas frecuentes
How many protons, neutrons and electrons does rhodium have?
Rhodium has 45 protons and 45 electrons (atomic number 45). Its most common isotope, rhodium-103, has 103 − 45 = 58 neutrons.
What is the electron configuration of rhodium?
[Kr] 5s¹ 4d⁸. In shells that is 2, 8, 18, 16, 1.
How many valence electrons does rhodium have?
Rhodium is a transition metal, so its valence electrons are spread over two shells; its outermost shell holds 1.
Where is rhodium on the periodic table?
In group 9, period 5, in the d-block. It is a transition metal.
