Classifying Matter Flashcards
Define Hardness
Measure of resistance that a solid matter shows to kinds of permanent deformation
Define Melting Point
The point of temperature that melts a soild
What are Mechanical characteristics
Stiffness, Strength, and toughness
Define Conductivity
Measure of a solid’s ability to conduct electricity
Define Facture
The way a solid breaks
What are the four classes of solids
- Ionic (metal+nonmetal)
- Metallic (metals)
- Molecular (non-metals)
- Covalent network (semi-metal/non-metals)
Ionic Crystals
- Metal + non metal
- Usually solid
- Ionic compounds are not very reactive and have filled energy lvls
- Transfer in electrons bcs of DEN
- Create strongest bond bcs neg and pos charges approach as close as possible
- High BP
Crystal lattice
Crystalline repeating pattern of atoms making solid structure
- Crystal lattice ions cannot be rearranged w/o breaking
Metallic Crystals
- Shiny, silvery, flexible, solid, good conductors
- Valence electrons become mobile bcs they are not held tightly, making them good conductors
- Flexible bcs non-directional bonds allow planes f ions to slide over each other easily while remaining bonded.
Molecular Crystals
- Low melting point, not hard, non conductors
- Molecules stacked as close as possible
- Intermolecular bonds are not strong = low melting points
Covalent network
- Hard, brittle, high BP, insoluble, non conductors
- 3-D arrangement of atoms continuously linked throughout the crystal by covalent bonds
- Covalent bonds are stacked = high melting point
- Electrons cannot move easily = cannot conduct electricity.
Group 1 (PT)
- Alkali Metals
- React w/ water to form alkaline (basic) solutions
- Most reactive
Group 2 (PT)
- Alkaline Earth Metals
- React w/ oxygen to form compounds called xides which reaction with water to form alkaline (base) solutions
Group 17 (PT)
- Halogens
- React w/ other elements to form compounds known as salts
Group 18 (PT)
- Noble Gases
- Do not combine naturally w/ any other elements
- Least reactive
