Atoms and ions

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Use scaffolded prompts to support learners to write about the formation of ions

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

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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.

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Learning objectives

Describe what happens to each subatomic particle when an ion is formed.
Explain what affects how easily ions are formed.

Introduction

Atomic structure is one of the most important topics in chemistry. Lots of other topics depend on understanding the structure of the atom and the properties of the subatomic particles – our Structure of the atom structure strip covers the basics. Ions are formed when electrons are lost and gained. The periodic table can help us understand ion formation.

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, 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

Additional scaffolding may be required to support learners to answer the questions. These could include a list of key words or add or remove prompts in the structure strip.

As learners grow in confidence, they may be able to attempt the follow-up question first and then use the structure strip to improve or self-assess their answer.

Keywords

atom, ion, nucleus, proton, electron, neutron, outer shell, inner shell,

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?

More resources for teaching atoms and ions

Challenge learners to apply problem-solving skills to a grid-based logic puzzle which relies on chemistry knowledge about ions, charge and periodic table groups.
Provide real-world context by introducing learners to the applications of highly charged ions including manufacturing computer chips, telling the time and hunting for dark matter.
Build an atom from scratch using protons, neutrons and electrons with this interactive simulation. Test different combinations to produce ions and unstable elements.
Learn how to identify metal and non-metal ions in unknown solutions with our identifying ions practical video for 14–16 year-olds.
Highlight diverse careers with our Chemistry: making the difference videos and let your learners be inspired by women helping to fix the future, such as Florence, chief technology officer and co-founder of a sustainable solutions company.

Follow-up question

Learners should answer the question after they have attempted the structure strip. The structure strip activates the required knowledge which learners can then apply to the question.

Explain why sodium forms 1⁺ ions but fluorine forms 1^- ions.

Answers

Suggested answers for the structure strip activity are given in the downloadable teacher notes (MS Word | PDF).

Answer to follow-up question

Sodium is in group 1 of the periodic table and hence has one electron in its outer shell. When it forms ions, this electron is lost, so the ion formed has a full outer shell of electrons. This leads to the sodium ion having one more positive proton than the number of negative electrons, leaving a 1⁺ charge.

Fluorine is in group 7. When it forms ions, it gains one electron and the ion formed has a full outer shell of electrons. This leads to the fluorine ion having one more negatively charged electron than the number of positive protons. So, a 1^- charge is left over.