Ionic bonding | Structure strip | 14–16 | Resource

No comments

Support learners to retrieve information on the diagrams used to represent ionic bonding

This resource is part of the Structure strip series of resources, designed to support literacy in science teaching.

Download this

Download the structure strips, which are printed five to a page, to support learners to find or retrieve information and write independently.

Find model answers in the teacher guidance.

Download All

Learning objectives

Describe ion formation.
Draw dot and cross diagrams of ionic bonding and explain how an ionic lattice is held together.
State the limitations of a range of models used to represent ionic bonding.

Introduction

Ionic bonding occurs when atoms lose and gain electrons to form ions and then the positively and negatively charged ions are attracted to each other. In this activity, learners will gain an understanding of the models and diagrams used to represent this and their limitations.

How to use structure strips

Structure strips are a type of scaffolding you can use to support learners to retrieve information independently. Use them to take an overview at the start of the topic, to activate prior knowledge, or to summarise learning at the end of a teaching topic.

Structure strips have sections containing prompts which are sized to suggest the amount that learners must write. Learners glue the strips into the margin of an exercise book and write their answers next to the sections, in full sentences. When learners have finished using the structure strip, they should have an A4 page set of notes and examples.

The strips are printed five to a page and will need to be trimmed to size. Find them on the second page of the student sheet.

Scaffolding

To further support learners to answer the questions you can include a list of keywords or add prompts to the structure strip.

As learners grow in confidence, they may be able to answer the question without the structure strip or attempt the question first and then use the structure strip to improve or self-assess their answer.

Metacognition

This activity supports learners to develop their metacognitive skills in the three key areas:

Planning: the strips provide scaffolding to plan the written response. Learners will decide where to gather information from (eg textbooks, own notes, revision websites). Ask learners: is the source of information I am using reliable?
Monitoring: learners are prompted by the questions in the structure strip and can check their answer against the prompts. Ask learners: have you covered all of the questions in the space provided? Do you need to change anything to complete the task?
Evaluation: learners can self-assess or ask a peer to check their work against the answers. Ask learners: did you achieve what you meant to achieve? What might you do differently next time?

Keywords

Bonding, dot and cross diagram. electron, ionic, ions, lattice, limitation, negative, positive.

More resources to teach ionic bonding

Use this step-by-step approach to help your 14–16 students master drawing ionic bonding dot and cross diagrams.
A set of differentiated Revew my learning worksheets with answers to identify learning gaps and misconceptions on the topic of bonding.
Steer students away from ionic bonding misconceptions with these ideas for your classroom.
Read more about learners’ ideas and misconceptions about chemical bonding, from the book ‘Beyond appearances’.

Follow-up question

Learners answer this question after attempting the structure strip. The structure strip activates the required knowledge which learners can then apply to this question.

Draw a dot and cross diagram to show what happens when atoms of sodium and oxygen react to produce sodium oxide. Discuss the advantages and limitations of the dot and cross diagram for this compound.

Answers

Suggested answers for the structure strip activity are given in the downloadable teacher notes.

Answers to follow-up question:

structure and bonding-03

Source: Royal Society of Chemistry

A dot and cross diagram showing the transfer of electrons from two sodium atoms to an oxygen atom to form the Na⁺ and O^2- ions in sodium oxide.

Explanation of charges: Each sodium ion has lost one electron, it now has 11 protons (+ charge) and 10 electrons (- charge) so has an excess charge of +1 leading to a 1⁺ charge on the ions.

The oxide ion has gained two electrons (one from each of the two sodium atoms), it now has eight protons (+ charge) and 10 electrons (- charge) so has an excess charge of -2 leading to a 2^- charge on the ion.

Evaluation of models: Dot and cross diagrams are good as they show what has happened in terms of electron transfer and make it clear that electrons have been lost and gained. They are limited because they do not show the giant lattice structure.