Difference Between Nuclear Fusion and Fission

The key difference between nuclear fusion and fission is that nuclear fusion is the combination of two or more atoms to create one large atom while nuclear fission is the division of a larger atom into two or smaller atomic particles.

In physics, an action always has an equal but opposite reaction. This is the ultimate philosophy in physics; thereby, all events and actions always have a corresponding opposite reaction. Furthermore, this is the main core of nuclear fusion and nuclear fission reaction as well. These are two different types of reactions that release certain amounts of energy. In simple chemistry, one creates smaller atoms while the other one combines atoms to form a larger one.

CONTENTS

1. Overview and Key Difference
2. What is Nuclear Fusion
3. What is Nuclear Fission
4. Side by Side Comparison – Nuclear Fusion vs Fission in Tabular Form
5. Summary

What is Nuclear Fusion?

Nuclear fusion is the fusing of two or more atoms to create a larger one. This type of reaction allows the atoms to combine in order to create a larger atom with a higher atomic number. One way of making a nuclear fusion is by allowing two or more nuclei to be near each other, which leads to a reaction which causes the atoms to stick together and combine to form as one.

Moreover, nuclear fusion takes place in nature naturally. A good example is the stars in the galaxy. According to theories, millions of stars have fused to become one giant massive star, we now refer to as the sun.

What is Nuclear Fission?

Nuclear fission is the opposite of nuclear fusion. It is the division of a large atom into two or more smaller pieces. In order to create fission, there are two conditions to be fulfilled:

1. A very slow neutron (for the process of division to occur)
2. A minimal amount of a particular substance (for fission to occur)

Furthermore, the minimal amount of substance is the critical mass, which depends on the neutron itself.  Nuclear fission does not occur in nature the way fusion does.

What is the Difference Between Nuclear Fusion and Fission?

Both nuclear fusion and fission releases very large and substantial amounts of energy and both share the same energy source, which is the atom itself. The key difference between nuclear fusion and fission is that nuclear fusion is the combination of two or more atoms to create one large atom while nuclear fission is the division of a larger atom into two or smaller atomic particles. Moreover, nuclear fusion occurs naturally, but nuclear fission does not.

Summary – Nuclear Fusion vs Fission

Both nuclear fusion and fission release very large and substantial amounts of energy and both share the same energy source, which is the atom itself. The key difference between nuclear fusion and fission is that nuclear fusion is the combination of 2 or more atoms to create 1 large atom while nuclear fission is the division of a larger atom into 2 or smaller atomic particles.

Reference:

1. Steinberg, Ellis P. “Nuclear Fission.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., Available here.

Image Courtesy:

1. “Nuclear fusion” By Someone – Someone (CC BY-SA 3.0) via Commons Wikimedia
2. “Nuclear fission reaction” By MikeRun – Own work (CC BY-SA 4.0) via Commons Wikimedia