---
title: "Silicon (Si): Atomic Mass, Electron Configuration & Properties"
url: https://www.moldraw.com/elements/silicon.html
description: "Silicon (Si), element 14: atomic mass 28.085, electron configuration [Ne] 3s² 3p², group 14, period 3, p-block metalloid. Melting and boiling point, density, electronegativity and shells."
lang: en
publisher: Scidart Academy
generated: 2026-11-03
---
14Si28.085

# Silicon (Si) – element 14

Silicon is a chemical element with the symbol **Si** and atomic number **14**. It is a metalloid in group 14, period 3 of the periodic table (p-block), and is a solid at room temperature.

Silicon (Si) has atomic number 14, atomic mass 28.085 u and electron configuration [Ne] 3s2 3p2.

[Download periodic table PDF](https://www.moldraw.com/printables/periodic-table.pdf)[Open interactive periodic table](https://www.moldraw.com/tools/free-chem-tools/interactive-periodic-table.html)

## Silicon facts

| Symbol | Si |
| --- | --- |
| Atomic number | 14 |
| Atomic mass | 28.085 u (g/mol) |
| Category | metalloid |
| Group | group 14 |
| Period | 3 |
| Block | p-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p2 |
| Noble-gas notation | [Ne] 3s2 3p2 |
| Electrons per shell | 2, 8, 4 |
| Valence electrons | 4 |

## Bohr model and shells

Silicon has 14 electrons in 3 shells: 2, 8, 4. Full configuration and noble-gas notation are in the table; work out any element or ion with the [electron configuration calculator](https://www.moldraw.com/tools/free-chem-tools/electron-configuration-calculator.html).

## Physical and atomic properties

| Melting point | 1687 K (1413.8 °C) |
| --- | --- |
| Boiling point | 3538 K (3264.8 °C) |
| Density | 2.329 g/cm³ |
| Electronegativity (Pauling) | 1.9 |
| Electron affinity | 134.068 kJ/mol |
| Ionization energies | 786.5, 1577.1, 3231.6 kJ/mol (1st, 2nd, 3rd) |
| Molar heat capacity | 19.789 J/(mol·K) |
| Discovered by | Jöns Jacob Berzelius |

Use the atomic mass in the [molar mass calculator](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html) for any formula containing Si.

## Position in the periodic table

Tap any element to open its page.

## Frequently asked questions

### What is the atomic mass of silicon?

The atomic mass of silicon is 28.085 u, so one mole of silicon atoms weighs 28.085 g.

### What is the electron configuration of silicon?

Silicon has 14 electrons: 1s² 2s² 2p⁶ 3s² 3p², or [Ne] 3s² 3p² in noble-gas notation. Electrons per shell: 2, 8, 4.

### How many valence electrons does silicon have?

Silicon has 4 valence electrons (group 14).

### Is silicon a metal?

Silicon is a metalloid: it has properties between metals and nonmetals.

### Where is silicon on the periodic table?

Silicon is in group 14, period 3, in the p-block.

Data: [Periodic-Table-JSON](https://github.com/Bowserinator/Periodic-Table-JSON) (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.