Metal plus non-metal

The idea

Generally metals form cations and non-metals form anions, so ionic compounds are typically formed when metals combine with non-metals.

A metal and a non-metal

In sodium chloride, sodium is the metal and chlorine is the non-metal.

Which ion do you think the metal forms in an ionic compound?

• A cation
• An anion
• A neutral atom

Sort the elements

Sort each element into the ion it forms in the compound named.

A pattern

In the three compounds, a metal combined with a non-metal. The metal formed the cation and the non-metal formed the anion.

Generally metals form cations and non-metals form anions, so ionic compounds are typically formed when metals combine with non-metals.

Notes

Generally, metals form cations and non-metals form anions. Ionic compounds are typically formed when metals combine with non-metals.

Check yourself

Ionic compounds are typically formed when…

Generally, what kind of ion does a metal form?

In magnesium sulfide, which ion is the anion?

Which pair of elements typically forms an ionic compound?

• two non-metals combine. Two non-metal atoms, such as two chlorine atoms in Cl₂, share electrons and form a covalent bond.
• two metals combine. Ionic compounds are typically formed when a metal combines with a non-metal.
• metals combine with non-metals — correct. Yes!
• A cation — correct. Yes!
• An anion. Generally non-metals form anions.
• A molecule. A molecule is a neutral entity of more than one atom. A metal generally forms a cation.
• Magnesium. Magnesium is the metal and forms the cation. The anion is sulfide.
• Sulfide — correct. Yes!
• Neither is an ion. Magnesium sulfide is an ionic compound, so it is made of a cation and an anion.
• Chlorine and chlorine, both non-metals. Two chlorine atoms form the molecule Cl₂ by sharing electrons.
• Oxygen and oxygen, both non-metals. Two oxygen atoms share two pairs of electrons to form the molecule O₂.
• Calcium (a metal) and oxygen (a non-metal) — correct. Yes!