Question

a. What is an ionic compound? b. In what form do most ionic compounds occur?

Short answer

a. An ionic compound consists of ions held by ionic bonds. b. Most ionic compounds are in crystalline form.

Step-by-step solution

Define an Ionic Compound

An ionic compound is a type of chemical compound composed of ions held together by electrostatic forces termed ionic bonding. These compounds are typically formed when a metal reacts with a non-metal.

Describe the Physical Form of Ionic Compounds

Most ionic compounds occur in a crystalline form. This means they form a crystal lattice structure where ions are arranged in a repeating pattern extending in all three spatial dimensions.

Key concepts

chemical compounds

Chemical compounds are substances made up of two or more different types of atoms bonded together.
These atoms combine in fixed ratios to form molecules or ionic structures.
In each compound, the elements lose their individual properties and exhibit new characteristics.
For example, water (H₂O) is a compound formed from hydrogen and oxygen. Though hydrogen is highly flammable and oxygen supports combustion, their compound, water, is used to extinguish fires.
By understanding chemical compounds, students can better predict how different elements will interact and form new substances.

ionic bonding

Ionic bonding is a type of chemical bond where atoms transfer electrons to achieve a full outer shell, resulting in the formation of ions.
Typically, this occurs between metals and non-metals. Metals, which have few electrons in their outer shell, tend to lose electrons and become positively charged ions (cations).
Non-metals, which have more electrons in their outer shell, tend to gain electrons and become negatively charged ions (anions).

• The electrostatic force of attraction between these oppositely charged ions holds them together in an ionic bond.
• For instance, consider sodium chloride (NaCl). Sodium (Na) loses one electron to become Na⁺, while chlorine (Cl) gains one electron to become Cl⁻.

This exchange of electrons creates a stable ionic compound.

crystal lattice structure

The crystal lattice structure is a unique formation seen in ionic compounds.
In this three-dimensional arrangement, ions are uniformly aligned in a repetitive pattern.
Each positive ion is surrounded by negative ions and vice versa, maximizing the attraction and minimizing the repulsion between oppositely charged ions.
This organization strengthens the compound significantly.
The high melting and boiling points of ionic compounds are due to the strong bonds in the crystal lattice.
Examples of ionic compounds that form crystal lattices include table salt (NaCl) and calcium fluoride (CaF₂).
This structured layout ensures the stability and durability of the compound, which is visualized in various crystal forms such as cubic or hexagonal shapes.