S2.1 The ionic model

Question 1

What are ions?

Answer 1

A charged particle. It has a charge as the number of protons do not equal the number of electrons.

Question 2

Cation

Answer 2

Positively charged ion. Formed when a metal atom loses electrons.

Question 3

Transition elements

Answer 3

Metallic elements located in groups 3–12 on the periodic table.

Question 4

How are cations and anions identified from their neutral atoms?

Answer 4

Cations form from metals losing electrons (positive charge), and anions form from non-metals gaining electrons (negative charge).

Question 5

How do you deduce the charge and symbol for ions?

Answer 5

Charge is deduced from electron loss (positive) or gain (negative). The symbol is the element’s symbol with a charge superscript.

Question 6

How to deduce the electron configuration of an ion from its symbol?

Answer 6

Adjust the neutral atom’s electron configuration for electron loss (cation) or gain (anion), aiming for a stable configuration.

Question 7

Ionic bonding

Answer 7

Electrostatic attraction between oppositely charged ions that holds the ions in close proximity.

Question 8

How to deduce the formula of an ionic compound?

Answer 8

Ionic compounds are neutral. The formula represents the simplest ratio of cations and anions. Use the “swap and drop” method for different charges to ensure overall neutrality.

Question 9

How are ionic compounds named?

Answer 9

Name the cation first (element name), then the anion with “-ide” ending. Use Roman numerals for transition metals with multiple charges. Ensure overall neutrality in the formula.

Question 10

Formula unit

Answer 10

The empirical formula for an ionic compound that represents the simplest ratio of ions making up the compound

Question 11

How can the formula for binary ionic compounds be deduced?

Answer 11

By considering the number of valence electrons.