Basic Chemistry Flashcards
Periodic table, reaction types, etc.
Valence electron periodic table trend
Increase from left to right and from top to bottom
Metals
-Elements on the left side and middle of the table
-Good electrical conductors
-Usually solid under standard conditions
-Ductible and malleable (can be stretched into other shapes)
Nonmetals
-Elements on the far right side of the periodic table
-Poor conductors
Metalloids
-Narrow staircase region on periodic table
-Poor to decent conductors
-Brittle
Metalloids (specific elements)
Boron, silicon, germanium, arsenic, antimony, tellurium
Group 1 Elements
Alkali metals; 1 valence electron; very reactive
Group 2 Elements
Alkaline earth metals; 2 valence electrons; reactive
Group 3-12 Elements
Transition metals; readily conduct electricity; most have multiple oxidation states; hard and durable
Group 13 Elements
First is metalloid boron, rest are metals; 3 valence electrons
Group 14 Elements
Carbon family; 4 valence electrons
Group 15 Elements
Nitrogen family; 5 valence electrons
Group 16 Elements
Chalcogens; 6 valence electrons, form -2 anions
Group 17 Elements
Halogens; 7 valence electrons; very reactive
Group 18 Elements
Noble/Inert gases; full valence shell; noreactive
Effective nuclear charge (Zeff)
Attractive force of the atom’s nucleus on the atom’s valence electrons
Effective nuclear charge periodic trends
Increases from left to right, decreases from top to bottom due to shielding
Atomic radius periodic trends
Decreases from left to right, increases from top to bottom (inverse relationship with Zeff)
Electrostatic repulsion
Electrons repel each other and want to be far away from each other, so radius increases for anions compared to neutral atom
Ionization energy
Energy required to remove one valence electron from a neutral atom in the gaseous state (first is always lower than the second due to reduced electrostatic repulsion after removal of first)
Ionization energy periodic trends
Increases from left to right, decreases from top to bottom
Main energy source of ATP
Energy stored in the third phosphate group’s bond - electrons in the other two phosphate groups strongly repel it
Oxidation reactions
Loss of electrons; fewer bonds to hydrogen and more to oxygen
Reduction reactions
Gain of electrons; more bonds to hydrogen and fewer bonds to oxygen
Oxidation order of Hydrocarbons
Alkynes, Alkenes, Alkanes
Polarity
Distribution of charge in a molecule
Hydrogen bonding
Strong charge based interactions between partial positive and partial negative charges on O-H, F-N, and N-H
Ions
Fully charged atoms or molecules
Types of atoms in order of increasing polarity
Nonpolar < Polar but not H-bonding < Molecules that use H-bonding < Ions
Steroids
Have polar groups, but are mostly nonpolar (4 ring structure)
Amphipathic
Molecule with both polar and nonpolar parts
Charge dipole
Formed from charge vectors within molecules, can cancel each other or have a net movement
Binary compound
Consists of exactly two different elements
Polyatomic ion
Charged species consisting of multiple atoms
Intramolecular forces
Hold atoms together
Covalent bond
-Bond between two nonmetals
-Sharing of valence electrons
Nonpolar covalent bond
2 elements in the bond have the same/very similar electronegativity (<0.5 eneg difference)
Polar covalent bond
Very different electronegativity values between two elements, resulting in uneven sharing of electrons (0.5-1.7 eneg difference)
Ionic bond
Between metal and nonmetal, complete transfer of electrons to nonmetal (>1.7 eneg difference)
Metallic bonds
Electrons become delocalized, creating an electron cloud
Intermolecular forces
Forces between separate molecules
London Dispersion Forces
-Weakest IMF
-Can be between any two molecules
-Result from chance temporary dipoles
-Stronger and more likely in larger molecules
Dipole-dipole interactions
Between polar molecules with stable dipoles
Hydrogen bonds
Between Hydrogen and either Oxygen, Fluorine, or Nitrogen (especially electronegative) ; both inter- and intra- molecular
Ion-dipole forces
Between an ion and a polar molecule
Ion-ion forces
IMF between two ions
