| A | B |
|---|
| An ion is | an atom or group of atoms that has become electrically charged |
| When an atom loses an electron | it loses a negative charge and becomes a positive ion |
| when an atom gains an electron | it gains a negative charge and becomes a negative ion |
| an ionic bond | is the attraction between two opossitely charged ions |
| When two ions come together | the opposite charges cancel out |
| Compounds are | electrically neutral |
| positively charged ions | have lost one or more electrons |
| Ions that are made of more than one atom | are examples of polyatomic ions |
| polyatomic ions is a group of atoms | that react as one |
| in naming ionic compounds | the name of the positive ion comes first followed by the name of the negative ion |
| The name of a positive ion | is usually the name of a metal |
| If the negative ion is an element | the end of its name changes to ide. |
| What kind of atom has a name change when it becomes an ion | if the negative ion is an element |
| What are the characteristic properties of ionic compounds | crystal shape; hight meling points; and electrical conductivity |
| An orderly three dimensional arrangement is called a | crystal |
| In an ionic compound | every ion is attracted to ions near it that have an opposite charge |
| Positive ions tend to be near | negative ions and farther from other positive ions |
| What happens when you heat table salt | When the particles have enugh energy to overcome the attraction, they break away |
| Ionic bonds are strong enough to cause all ionic compounds | to be solid at room temperature |
| How does dissolving salt in water allow electricity to flow | ionic compounds dissolve in water, the ions separate, and then move freely; the solution conducts electricity |
| Why are compounds in an ionic compound attracted to each other | because ionic bonds are two oppositely charged ions that attract |
| A sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge | Sodium and Chloride have oppostive charged ions that attract which is an IONIC BOND |
| In an ionic compound | the positive ions blance the charge of the negative ions and the compound is ELECTRICALLY NEUTRAL |
| A chemical bond formed when two atoms share ELECTRONS is called | a covalent bond |
| Ionic bonds form between | metals and nonmetals |
| Covalent bonds form between | two or more NONMETALS |
| In a covalent bond | both atoms attract the two shared eletrons at the same time |
| Some atoms pull more strongly on the shared electrons. What is the result | the electrons move closer to one atom causing the atoms to have a slight electrical charge |
| A covalent bond in which electrons are shared unequally | is polar |
| In a polar, it is like a tug of war game | where one atom is slightly stronger than the other atom |
| When the valence electron is shared equally | the bond is nonpolar |
| Differences in the attractions between molecules lead to | different properties in polar and nonpolar compounds |
