Term
| What are the 3 phases of materials and how do they differ? |
|
Definition
| Gas, liquid, solid weak-strong attraction between molecules |
|
|
Term
| what is long and short range order? |
|
Definition
Short range(Liquid) – spatial relationship between atoms 5-10 neighbors apart
Long range(solid) – spatial relationship of molecules repeated millions of times
**gases have no order** |
|
|
Term
| What is an example of long range order? Short range? |
|
Definition
Crystalline – long range
Amorphous – short range |
|
|
Term
| What is an ionic bond and what is an example of it? |
|
Definition
| ionic bond is where one molecule gives an electron to another molecule, EX: table salt |
|
|
Term
|
Definition
| two molecules sharing electrons |
|
|
Term
| What is an example of a covalent bond? |
|
Definition
|
|
Term
|
Definition
| Valence electrons are shared by all the atoms that make up the object |
|
|
Term
| What is: Positive cores surrounded by a cloud of negative mobile valence electrons. |
|
Definition
|
|
Term
| What is an example of a metallic bond? |
|
Definition
|
|
Term
| What are secondary bonds? |
|
Definition
| Partial charges from an uneven distribution of electrons around an atom or molecule |
|
|
Term
| What is another name for a secondary bond? |
|
Definition
|
|
Term
| What are secondary bonds important in determining? |
|
Definition
| the properties of polymers |
|
|
Term
| What is a permanent dipole? What do these result in? |
|
Definition
| one atom has permanent positive charge and one has negative charge – result in weak bonds |
|
|
Term
| What is a fluctuating dipole? |
|
Definition
| uneven distribution of electrons around atoms resulting in weak bond |
|
|
Term
|
Definition
| special permanent dipole, only one electron and when pulled away hydrogen nucleus left partially unshielded, strong dipole results |
|
|
Term
| How do the atomic bonds of metals allow them to be ductile? |
|
Definition
| Electron cloud allows atoms to slide past each other with little difference |
|
|
Term
| Explain how the ionic bonds of ceramics make this material strong but brittle. |
|
Definition
| Atoms slide past each other encounter an atom with same charge – repulsion (brittle when pulled apart) strong when compressed |
|
|
Term
| Why are ceramics suited to replace lost tissue structure? |
|
Definition
| Translucent and comes in many colors/shades |
|
|
Term
| What is the atomic structure of polymers like? |
|
Definition
| Long chains of covalently bonded, repeating units |
|
|
Term
| What are polymers used for in dentistry? |
|
Definition
| Mouthguards, bleaching tray, dental instruments, composite filling material |
|
|
Term
|
Definition
| mixture of ceramic and polymer |
|
|
Term
|
Definition
| suspensions of one material in another (impression material & fluoride foam) |
|
|
Term
|
Definition
| 2 liquids that do not blend together to form one liquid (transformation from liquid to a gel) |
|
|
