5 Steps to a 5 AP Chemistry

260 

Nuclear Chemistry

IN THIS CHAPTERR

Summary:Radioactivity, the spontaneous decay of an unstable isotope to a

more stable one, was first discovered by Henri Becquerel in 1896. Marie Curie

and her husband expanded on his work and developed most of the concepts

that are used today.

Throughout this book you have been studying traditional chemistry and

chemical reactions. This has involved the transfer or sharing of electrons from

the electron clouds, especially the valence electrons. Little has been said up

to this point regarding the nucleus. Now we are going to shift our attention

to nuclear reactions and, for the most part, ignore the electron clouds.

Keywords and Equations

No specific nuclear equations are provided, but review first-order equations

in the Kinetics chapter.

Nuclear Reactions

Balancing Nuclear Reactions

Most nuclear reactions involve breaking apart the nucleus into two or more different ele-

ments or subatomic particles. If all but one of the particles is known, the unknown parti-

cle can be determined by balancing the nuclear equation. When chemical equations are

balanced, coefficients are added to ensure that there are the same number of each type of

atom on both sides of the reaction arrow. To balance nuclear equations, we ensure that there

is the same sum of both mass numbers and atomic numbers on both the left and right

CHAPTER

17

KEY IDEA

KEY IDEA