Predict the formula of beryllium fluoride.
Be gives 2+, fluoride is F-. Two fluorides per beryllium: BeF2. It is used in nuclear reactor fuel processing.
What Is the Charge of Beryllium?
Beryllium commonly forms Be2+ in introductory ionic compounds.
Beryllium is assigned a 2+ charge in compounds such as BeCl2 and BeO. Be aware, though, that real beryllium bonds have strong covalent character — more than any other Group 2 element.
| Element | Beryllium |
|---|---|
| Symbol | Be |
| Atomic number | 4 |
| Common ionic charge | +2 |
| Common ions | Be2+ |
Visual reference
Beryllium element image and atomic model
Images are used as visual references; charge rules still depend on the compound.
Why Beryllium lets go of two electrons
Beryllium's configuration is 1s2 2s2. Removing both 2s electrons exposes the helium core, giving the 2+ assignment. Because the resulting ion would be tiny and doubly charged, it polarizes nearby electron clouds so strongly that its bonds end up partly covalent.
Where Beryllium formulas usually go wrong
Treating BeCl2 like a typical ionic salt. Molten BeCl2 barely conducts electricity — a giveaway that the bonding is covalent — yet for formula-writing and naming you still use the 2+ assignment.
Worked example: Be in a formula problem
Be2+ in real compounds
BeCl2
Beryllium chloride
Be2+ balances chloride ions.
BeO
Beryllium oxide
Beryllium can form oxides where total positive and negative charge balances.
Questions students ask about beryllium
Why doesn't beryllium react with water like magnesium and calcium do?
Its small size and high charge density create a tough protective oxide layer, and its bonds resist the ionization that drives those reactions in heavier Group 2 metals.
Is Be2+ found free in solution?
Not really free — in water it exists as [Be(H2O)4]2+, gripping four water molecules tightly. Beryllium compounds are also highly toxic, so this is lab-lecture knowledge, not hands-on.
Does beryllium ever form a 1+ ion?
No stable Be+ compounds exist. The 2s2 pair goes together: beryllium is 2+ or nothing in ordinary chemistry.
How do I use this charge in formulas?
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Where this data comes from
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.