Atoms, Isotopes and Ions: Free Course

About this course

Study Atoms, Isotopes and Ions in this free English video course from Khan Academy. The classroom preserves all 9 published source recordings, totaling approximately 48m, with their original lesson titles and sequence. The selected curriculum focuses on chemical representations, relationships and worked reasoning. Use the videos to follow an explanation, examine an example and develop a study output you can check independently. The course title describes this recorded subject or learning track; your study can extend beyond watching through the practical activities below.

Course at a glance

What you’ll learn

• Follow the explanation and worked reasoning in “Protons, neutrons, and electrons in atoms”, then describe the main idea in your own words.
• Follow the explanation and worked reasoning in “Elements and atomic number”, then describe the main idea in your own words.
• Follow the explanation and worked reasoning in “Worked example: using the mass number equation”, then describe the main idea in your own words.
• Follow the explanation and worked reasoning in “Introduction to ions”, then describe the main idea in your own words.
• Connect examples across Atoms, Isotopes and Ions by identifying the terms, assumptions and methods they use.
• Create a small independent practice output and check it against the relevant teaching explanation.

Skills you’ll gain

• Chemical reasoning
• Units and notation
• Molecular concepts
• Worked examples

Course Overview

The source curriculum is presented as a complete recorded video edition of Atoms, Isotopes and Ions. Representative lessons include “Protons, neutrons, and electrons in atoms”, “Worked example: using the mass number equation” and “Wave particle duality”. These recordings give concrete examples to revisit while building chemical representations, relationships and worked reasoning. Their place in the lesson list is preserved, so you can return to a particular explanation without losing its source position. Introductions, demonstrations, examples, reviews and compilations remain included whenever they appear in the original playlist. Reading a lesson title is useful for locating a topic; working through its reasoning and checking a practice attempt is what makes the recording valuable for learning.

How to study the course

• Videos 1–2: this part of the source list includes “Protons, neutrons, and electrons in atoms” through “Elements and atomic number”. Define the particles, quantities and conditions. Keep a brief working note, revisit an unclear explanation and test one example before moving to another part of the material.
• Videos 3–4: this part of the source list includes “Isotopes” through “Worked example: using the mass number equation”. Use symbols and units consistently. Keep a brief working note, revisit an unclear explanation and test one example before moving to another part of the material.
• Videos 5–6: this part of the source list includes “Average atomic mass” through “Introduction to ions”. Connect a representation to its chemical meaning. Keep a brief working note, revisit an unclear explanation and test one example before moving to another part of the material.
• Videos 7–9: this part of the source list includes “Worked example: calculating ion charge” through “Wave particle duality”. Check a worked result against the starting information. Keep a brief working note, revisit an unclear explanation and test one example before moving to another part of the material.

Who is this for?

This course suits students and returning learners studying the named chemistry topic. It also provides a recorded reference for revisiting a topic after an earlier lesson or study attempt. Choose examples appropriate to your background and allow time to work through the method instead of judging understanding only by how familiar the terminology sounds.

Before you start

Basic arithmetic and earlier atomic or molecular concepts are helpful. Keep notes on symbols, units and the conditions stated in each example.

Put the lessons into practice

Select an example from the course and reproduce the reasoning with clear symbols and units. Identify the particles, quantities or conditions involved. Try a second example with a changed value or substance when the lesson demonstrates that type of comparison. Explain which rule or relationship supports each step, then check the result for consistency with the starting information. Build a short glossary linking the main terms to examples from the recordings. Use written study tasks; performing a laboratory experiment is not required for this video course.

This optional study activity is provided by WikiFree for independent practice. Keep your working notes and use the relevant classroom recording to check a step, definition or interpretation. It is not an instructor-marked assignment.

Certificate / Assessment

Watching the public videos and using WikiFree completion tracking does not award a certificate, academic credit, an examination voucher or instructor assessment. Use your practice output to review what you can explain and repeat independently. The recorded lessons provide study material; completion tracking records your progress through that material.

Frequently asked questions

Provider: Khan Academy. Videos play from the Khan Academy channel on YouTube.