Ionic Bonds Chapter 15

What is an ionic bond? A bond that occurs typically between a metal and non-metal. The bond involves a transfer of electrons from one atom to another atom. The atom that loses electrons becomes a cation. Usually a metal. The atom that gain electrons becomes an anion. Usually a non-metal. It is the oppositeness in charge that keeps the ions bound together. Ionic bonds are very strong.

Valence Electrons The electrons in the highest occupied energy level. These are the electrons involved in bonding. Valence electrons can be determined by electron configuration or by column number for Group A elements.

How many valance electrons in… Hydrogen Beryllium Oxygen Nitrogen Argon Helium

Octet Rule & Noble Gas Configurations Atoms are stable when they achieve an electron configuration like a noble gas. This means that most atoms try to achieve 8 electrons in their outermost energy level. Not everything obeys the octet rule; there are exceptions. Ex. Helium, Hydrogen

Formation of Cations How many total electrons does sodium have? Na = 11 electrons How many valance electrons does sodium have? Na = 1 valence electron Will sodium lose 1 electron or gain 7 electrons to obey the octet rule? Lose 1e- How many total electrons does sodium ion have? Na ion=10 electrons What neutral atom has 10 electrons? Neon What is sodium’s charge? Na+

Formation of Cations How many total electrons does magnesium have? Mg = 12 electrons How many valance electrons does magnesium have? Mg = 2 valence electron Will magnesium lose 2 electron or gain 6 electrons to obey the octet rule? Lose 2e- How many total electrons does magnesium ion have? Mg ion=10 electrons What neutral atom has 10 electrons? Neon What is magnesium's charge? Mg2+

Formation of Anions How many total electrons does chlorine have? Cl = 17 electrons How many valance electrons does chlorine have? Cl = 7 valence electron Will chlorine lose 7 electrons or gain 1 electron to obey the octet rule? Gain 1e- How many total electrons does chlorine ion have? Cl ion=18 electrons What neutral atom has 18 electrons? Argon What is chlorine’s charge? Cl-

Electron Dot Structure A simple structure that represents the valence electrons of an atom as dots surrounding the symbol of an atom. Electrons go around each side of the element first before doubling up.

Electron dot structures for … Hydrogen Beryllium Oxygen Nitrogen Argon Helium

Using Electron Dot Structures to explain Ionic Bonding. Bond together Potassium and Phosphorus Bond together Magnesium and Nitrogen