Chemistry is about electrons. That is to say that chemistry is about where electrons are, what they are doing, which nuclei are attracting them and how strongly they are feeling those attractions. This unit, however is not about electrons at all (at least in the normal way we think about them) and for that reason it is not really chemistry.
That, of course, raises the question “why is nuclear science included in a chemistry text?” The answer is, unfortunately, not a good one. Nuclear science is really part of high energy physics. The scientists who do the work are physicists, and in college this topic is part of the physics department. However, it is very rarely touched on in high school physics classes and it can be found on many standardized chemistry tests. So, we are including it here so that, if it is part of your class, or if you are taking a standardized test, you have the information you need.
Studying nuclear science at the basic level requires you to understand the basics of atomic structure, which may have been discussed earlier in your course. In addition, you need to know a little about what holds the nucleus together and a little bit about the things that make up protons and neutrons. You will also need to understand the symbols that chemists and physicists use for nuclear particles.
Once you have these basics, you will need to know about the common particles that are involved in nuclear science. You will then be ready to look at nuclear reactions - both the types of reactions that are possible and how these reactions are "balanced."
You will need to learn about the energy associated with these reactions (including nuclear power and nuclear bombs). Lastly, you should learn about the kinetics of these reactions which is always first order. This leads to the idea of half-lives (which can be understood through an analogy) and which can be used to find the age of everything from stone-age artifacts to the rocks in which dinosaur bones are found.