H Chemistry: Unit 4 Flashcards
periodicity
study of the trends on the periodic table
octet rule
every element on the periodic table wants 8 electrons in their highest energy level(noble gas configuration) except hydrogen and helium
oxidation number
charge an atom has when it acquires an octet; the oxidation number for transitional elements vary
metals
solids and good conductors of heat and electricity
non-metals
gases and poor conductors of heat and eletricity
metalloid
moderate conductors of heat and electricity
group 1 elements
alkali metals
group 2 elements
alkaline earth metals
group 6 elements
chalcogens
group 7 elements
halogens
group 8 elements
noble gases
atomic radius
half the distance between the nuclei of 2 like atoms; measured in angstroms
atomic radius trend
increases as you move down and left
ionization energy
energy required to remove an electron from an atom; measured in volts
ionization energy trend
increases as you move up and right
electronegativity
ability of an atom to attract electrons to itself; measured in Paulings’
electronegativity trend
increases as you move up and right
shielding effect
electrons closer to the nucleus shield the outer electrons from the pull of the nucleus; increases with the number of electrons
shielding effect trend
increases as you move down and right
ionic radius
size of an atom compared to the atomic radius when a atom gains or loses electrons
chemical bond
bond between atoms
ionic bond
electrostatic force between atoms(cation and anion); formula unit or salt
cation
positive
anion
negative
properties of an ionic compound
1.form a crystal lattice
2.high melting and boiling points
3.salts are solid, hard, and brittle
4.form an electrolyte
lattice energy
energy required to remove an ion from a crystal
electrolyte
substance that conducts electricity when dissolved
monatomic ion
ion made up of one atom; everything on periodic table
polyatomic ion
ion made of more than 1 atom
an ionic compound is
neutral
naming ionic compounds- cation first
-if the cation is an element on the periodic table, use its name
-if the cation is polyatomic, use its unique name
-if the cation is a transition metal with more than one share, use a Roman numeral to indicate its charge
naming ionic compounds- anion second
-if the anion is monatomic off the periodic table, use its root name and add the suffix “-ide”
-if the anion is polyatomic, use its unique name on the periodic table
covalent bond
bond between atoms where electrons are shared; molecule
the covalent bond occurs when
attraction and repulsion forces are in balance
attraction forces
nucleus of 1 atom attracted to the electrons of the other
repulsion forces
nuclei of both atoms and the electrons of both atoms repel each other
single covalent bond
sigma bond; bond between atoms where one pair of electrons are shared
double covalent bond
1 sigma & 1 pi; bond between atoms where 2 pairs of electrons are shared
pi bond
bond between parallel orbitals that overlap
triple covalent bond
1 sigma & 2 pi; bond between atoms where 3 pairs of electrons are shared
bond length
distance between bonded nuclei; the shorter the bond, the stronger it is; multiple bonds are shorter and stronger
bond dissociation energy(BDE)
energy required to break a covalent bond
diatomic gases
7 elements on the periodic table that exist in nature in pairs; I H N Cl O Br F
resonance structure
lewis structure that can be drawn in more than one way to illustrate the sharing of a double bond; use a double arrow
expanded octet
center atom will occasionally bond with empty d orbitals and have more than 8 electrons in the highest energy level(s & p)
VSEPR(valence shell electron pair repulsion) theory
unshared pairs of electrons on the center atom in a lewis structure take up space
A.X.E Notation
A- center atom
X- atoms that re bonded to the center atom
E- unshared pairs of electrons
AX2
linear
AX3
trigonal planar
AX4
tetrahedral
AX3E
trigonal pyramidal
AX2E2
bent
AX5
trigonal bipyramidal
naming molecules- prefix method
prefixes indicate the number of atoms in the molecule
naming molecules- 1
mono
naming molecules- 2
di
naming molecules- 3
tri
naming molecules- 4
tetra
naming molecules- 5
penta
naming molecules- 6
hexa
naming molecules- 7
hepta
naming molecules- 8
octa
naming molecules- 9
nona
naming molecules- 10
deca
naming molecules
- first element- use a prefix and its name off of the periodic table
- second element- use a prefix and its root name off periodic table with the “-ide” suffix
- omit “mono” from first element
acid
substance that donates hydrogen to a solution and lowers pH; anion determines acid name
