Beryllium

ALKALINE EARTH METAL

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

Beryllium is a chemical element with symbol Be and atomic number 4. It is created through stellar nucleosynthesis and is a relatively rare element in the universe. It is a divalent element which occurs naturally only in combination with other elements in minerals.

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Quick Facts

Atomic Number 4

Period 2

Group 2

Phase Solid

Appearance white-gray metallic

About Alkaline Earth Metals

Alkaline earth metals (Group 2) are reactive metals, though less so than alkali metals. They typically lose two electrons to form cations with a +2 charge.

History

Discovered By Louis Nicolas Vauquelin

Named By Unknown

Physical Properties

Atomic Mass 9.01218315

Density 1.85 g/L

Molar Heat 16.443 J/(mol·K)

Phase Transition (Melting & Boiling Points)

Beryllium melts at 1560 K and boils at 2742 K.

Atomic Properties

Electron Config [He] 2s2

Electronegativity 1.57

Electron Affinity -48 kJ/mol

Ionization Energy 899.5 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

Source: Wikipedia

External Resources

Wikipedia PubChem Royal Society of Chemistry Periodic Videos (YouTube)

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.