Most transition elements can form more than one type of ion. Ion Name Example of compound Cu + Copper I ion Copper I oxide, Cu 2 O Cu 2 + Copper II ion Copper II oxide, CuO Fe 2 + Iron II ion Iron II chloride, FeCl 2 Fe 3 + Iron III ion Iron III chloride, FeCl 3 The II in the name tells you that the ion has a charge of 2 + . What do the I and III show?

The II in the name tells you that the ion has a charge of 2 + . Similarly, the I in the name tells us that, the ion has a charge of 1 + , and the III in the name tells us that, the ion has a charge of 3 + . Transition elements generally can form different ions because of their outer electrons in two different sets of orbitals.

E M B I B E

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 1

HARD

Upper Secondary: IGCSE

IMPORTANT

Earn 100

Draw a diagram to show what happens to the electrons, when a sodium atom reacts with a chlorine atom?

Important Questions on Atoms Combining

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 2

What is an ionic bond?

HARD

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 3

Describe in your own words the structure of solid sodium chloride, and explain why its formula is

NaCl

.

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 4

Explain why a magnesium ion has a charge of

2 +

.

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 4

Explain why the ions in magnesium oxide stay together.

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 4

Explain why magnesium chloride have no overall charge.

MEDIUM

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Q>Q 4

Explain why the formula of magnesium chloride is

{MgCl}_{2}

.

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Exercise 5>Q 1

The formula of sodium sulphite is

{Na}_{2} S

. What does this _$2$show?

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 4 - Atoms Combining>Exercise 6>Q 1

Most transition elements can form more than one type of ion.

Ion	Name	Example of compound
${Cu}^{+}$	Copper $(I)$ ion	Copper $(I)$ oxide, ${Cu}_{2} O$
${Cu}^{2 +}$	Copper $(II)$ ion	Copper $(II)$ oxide, $CuO$
${Fe}^{2 +}$	Iron $(II)$ ion	Iron $(II)$ chloride, ${FeCl}_{2}$
${Fe}^{3 +}$	Iron $(III)$ ion	Iron $(III)$ chloride, ${FeCl}_{3}$