Ions

Question 1

What is a cation?

Answer 1

A cation is a positively charged ion formed when an atom or group of atoms loses one or more electrons. They usually form from hydrogen or metals.

Question 2

What is an anion?

Answer 2

An anion is a negatively charged ion formed when an atom or group of atoms gains one or more electrons. They usually form from non-metals.

Question 3

What is bonding like in ionic compounds?

Answer 3

Ionic bonds are strong electrostatic forces of attraction between oppositely charged ions. For example, when sodium reacts with chlorine to form sodium chloride, NaCl:
Electrons transfer from sodium atoms to chlorine atoms. Na+ ions and Cl- ions form and attract each other.

Question 4

What is the structure of ionic compounds?

Answer 4

The ions in ionic compounds form a lattice structure that has a regular arrangement of ions and ionic bonds between opposite charged ions.

Question 5

What are the melting and boiling points of ionic compounds?

Answer 5

Ionic compounds usually have high melting and boiling points. As a result, they are in the solid state at room temperature. You can explain this in terms of bonding and structure - there are many strong ionic bonds and large amounts of energy must be transferred to the lattice structure to break these bonds.

Question 6

What is solubility in water like in ionic compounds?

Answer 6

Ionic compounds are often soluble in water. They dissolve to form aqueous solutions.

Question 7

Why don’t ionic compounds conduct electricity when in a solid state?

Answer 7

The ions are not free to move around in a solid. Although ions are electrically charged, they are held in fixed positions in the lattice structure.

Question 8

Why do ionic compounds conduct electricity when molten or in an aqueous solution?

Answer 8

The ions are free to move around when in a liquid or dissolved in water. This means they can carry electric charge from place to place.