Boro (B): Bohr Model, Protons, Neutrons & Electrons
Boro is element number 5, a metalloid in group 13, period 2. Its atom has 5 protons, 6 neutrons and 5 electrons arranged in 2 shells: 2, 3.
- 5 protons
- 6 neutrons
- 5 electrons
Protons, neutrons and electrons in boron
El atomic number of boron is 5, so every boron atom has 5 protons. A neutral atom has the same number of electrons, 5. The number of neutrons depends on the isotope: neutrons = mass number − atomic number. For boron-11, that is 11 − 5 = 6 neutrons. Boron has 2 stable isotopes, with 5, 6 neutrons.
How to draw the Bohr model of boron
- Draw the nucleus and write 5 p⁺ y 6 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 3 electrons on it.
- Check: 2 + 3 = 5 electrons, the same as the number of protons.
Electron configuration
The electron configuration of boron is [He] 2s² 2p¹. Its 3 outer electrons decide how it reacts: it usually shares electrons in covalent bonds.
Key facts about boron
| Symbol | B |
|---|---|
| Atomic number | 5 |
| Relative atomic mass | 10.81 |
| Group · period · block | group 13 · period 2 · p-block |
| Tipo | Metalloide |
| State at 25 °C | solid |
| Capas electrónicas | 2, 3 |
| Electron configuration | [He] 2s² 2p¹ |
| Electrones de valencia | 3 |
| Common ion | — |
| Electronegativity (Pauling) | 2.04 |
| First ionisation energy | 8.30 eV (801 kJ/mol) |
| Atomic radius (empirical) | 85 pm |
¿Dónde boron sits on the periodic table
Preguntas frecuentes
How many protons, neutrons and electrons does boron have?
Boron has 5 protons and 5 electrons (atomic number 5). Its most common isotope, boron-11, has 11 − 5 = 6 neutrons.
What is the electron configuration of boron?
[He] 2s² 2p¹. In shells that is 2, 3.
How many valence electrons does boron have?
3. Boron is in group 13, and its outer shell holds 3 electrons.
Where is boron on the periodic table?
In group 13, period 2, in the p-block. It is a metalloid.
