Section 1: Ion Formation Ions are formed when atoms gain or lose valence electrons to achieve a stable octet electron configuration. K What I Know W What I Want to Find Out L What I Learned

Essential Questions What holds atoms together in a chemical bond? How do positive and negative ions form? How does ion formation relate to electron configuration? Copyright © McGraw-Hill Education Ion Formation

Vocabulary Review New octet rule chemical bond cation anion Ion Formation Copyright © McGraw-Hill Education

Valence Electrons and Chemical Bonds A chemical bond is the force that holds two atoms together. Chemical bonds form by the attraction between the positive nucleus of one atom and the negative electrons of another atom. Atom’s try to form the octet—the stable arrangement of eight valence electrons in the outer energy level—by gaining or losing valence electrons. Copyright © McGraw-Hill Education Ion Formation

Add link to concepts in motion animation from page 207 here. Interactive Table – Electron-Dot Structures Concepts in Motion FPO Add link to concepts in motion animation from page 207 here. Copyright © McGraw-Hill Education Ion Formation

Positive Ion Formation A positively charged ion is called a cation. This figure illustrates how sodium loses one valence electron to become a sodium cation. Copyright © McGraw-Hill Education Ion Formation

Metal Ions Metals are reactive because they lose valence electrons easily. This table summarizes the ions formed by metal ions in groups 1, 2, and 13. Copyright © McGraw-Hill Education Ion Formation

Transition Metal Ions Transition metals commonly form 2+ or 3+ ions, but can form greater than 3+ ions. Other relatively stable electron arrangements are referred to as pseudo-noble gas configurations. Copyright © McGraw-Hill Education Ion Formation

Negative Ion Formation An anion is a negatively charged ion. The figure shown here illustrates chlorine gaining an electron to become a chlorine ion. As shown in the table below, nonmetal ions gain the number of electrons required to fill an octet. Some nonmetals can gain or lose other numbers of electrons to complete an octet. Copyright © McGraw-Hill Education Ion Formation

Review Essential Questions Vocabulary What holds atoms together in a chemical bond? How do positive and negative ions form? How does ion formation relate to electron configuration? Vocabulary chemical bond cation anion Copyright © McGraw-Hill Education Ion Formation