Chem- Ch 2 Flashcards
(23 cards)
Periodic table
Organized the elements according to their atomic number
-pattern of similar properties
Periods
Rows
-based on same principle energy level, n
Groups
Columns
-elements in the same group have the same valence shell electron configuration
Metals
- shiny (lustrous)
- conduct electricity well
- malleable
- ductile (able to pull into wires)
-mostly on left and middle of table
Nonmetals
- full
- poor conductors
- brittle
-found mostly on right side of table
Metalloids
Characteristics of both metals and nonmetals
-found in a stair step pattern starting with Boron
Effective nuclear charge (Z eff)
Net positive charge experienced by electrons in the valence shell
Z eff trend
- increase across a period
- little charge down a group
Atomic radius
Decreases across a period
Increase down a group
Ionic radius
-size of a charged species
Ionic radius trends
- largest nonmetallic and smallest metal radii exist at metalloid boundary
- cations = smaller than neutral atom
- anions = larger than neutral atom
Ionization energy
Amount of energy needed to remove an electron from the valence shell of a gaseous species
Ionization energy trends
Increases across a period
Decrease down a group
Electron affinity
Amount of energy released when a gaseous species gains an electron in its valence shell
Electron affinity trends
Increases across a period
Decreases down a group
Electronegativity
Measure of the attractive force of the nucleus for electrons within a bond
Electronegativity trends
Increases across a period
Decreases down a group
Alkali metals
Oxidation state of +1
- prefer to lose electron
- really reactive –don’t exist in neutral state naturally
Alkaline earth metals
Oxidation state of + 2
Lose two electrons to be like noble gas
Chalcogens
Oxidation state of -2 or +6
Biologically very important
Halogens
Oxidation state of -1
Prefer gaining electrons
Highest electronegativities
Noble gases
Fully filled valence shell
Inert gases
High ionization energies
Nonexistent electronegativities and electron affinities
Transition metals
Unique -take on multiple oxidation states
-explains ability to form colorful complexes with nonmetals on solution and their utility in certain biological systems
