mod 1 ch 1 Flashcards
label
A: Mass number (protons + neutrons)
X: Element symbol (one or two letters)
Z: atomic number (number of protons)
what is this
the atomic mass, weighted average mass in amu (atomic mass units) of an elements isotope
define isotopes
atoms with the same atomic number but different mass numbers
what is the solution to the wave equation
wave function or orbital
what are the four different kinds of orbitals
s, p, d, f
what are the three configurations a p orbital can have
each orbital can have up to two electrons that must have ___________ _______.
opposite spins
label
2 - s orbital (2)
8 - s and p orbitals (2 + 6)
18 - s, p, and d orbitals (2 + 6 + 10)
as electron shells get farther from the nucleus
they get bigger and increase in energy
when filling orbitals, electrons must fill up the same energy orbital before…
pairing up with an electron of opposite spin
valence shell
outermost shell occupied by electrons
valence electrons
electrons in the outermost shell (valence shell)
what is chemical bonding theory
atoms form bonds because the resulting compound is more stable than the separate atoms
ionic bonds
formed as the result of electron transfers, ions formed held together by an electrostatic attraction
label the product
IONIC COMPOUND
label the product
COVALENT COMPOUND
covalent bond
formed by sharing of electrons between nonmetals
It is energetically favorable for non-metallic elements to ________ ________ in order to achieve electron configuration of nearest inert gas
SHARE ELECTRONS
how many covalent bonds does hydrogen form
one
how many covalent bonds does carbon form
four
how many covalent bonds does oxygen form
two
how many covalent bonds does nitrogen form
three
what does the valence bond theory state
covalent bonds form when two atoms approach each other closely so that an orbital containing 1e- overlaps with another orbital containing 1e-
what is bond length
ideal distance between nuclei that leads to maximum stability
when a bond breaks, energy is
absorbed
when a bond is formed, energy is
released
what are the hybridizations strongest to weakest
sp - strongest
sp2 - middle
sp3 - weakest
if an atom only has sigma bonds its hybridization is
sp3
if an atom has one double bond and two single bonds its hybridization is
sp2
if an atom has one triple bond and a single its hybridization is
sp
what are the hybridizations bond lengths from longest to shortest
sp3 - longest bond length
sp2 - middle
sp - shortest bond length
what is the molecular geometry of an sp2 hybridized atom and what is its bond angle
trigonal planar, 120
what is the molecular geometry of an sp3 hybridized atom and what is its bond angle
tetrahedral, 109.5
what is the molecular geometry of an sp hybridized atom and what is its bond angle
linear,180
what is the Formal Charge formula
FC = valence electrons - lines - dots
what are the three ways oxygen exists
what are the three ways carbon exists
what are the three ways nitrogen exists
in resonance if an atom must have a charge but the negative charge on the most ____________ atom
electronegative
what are the three types of resonances
type I - when a molecule has a positive charge adjacent to a double/triple bond
type II - when a molecule has a negative charge or a lone e- pair adjacent to a double or triple bond
type III - when the molecule has BOTH a positive and negative charge adjacent to each other OR if the molecule has no charge but at least one double or triple bond
what are the steps for type I resonance?
- start with the positive charge and label it #1. count through three consecutive atoms making sure there is a double or triple bond between atoms #2 and #3
- break the double/triple bond between atoms #2 and #3 and put it between atoms #1 and #2. place the positive charge on atom #3
what are the steps for type II resonance?
- start with the positive charge and label it #1. count through three consecutive atoms making sure there is a double or triple bond between atoms #2 and #3
- lone pair/negative charge on atom #1 makes a double bond between atoms #1 and #2. the double/triple bond between atom #2 and #3 breaks and leave a lone pair on atom #3.
what are the steps for type III resonance?
- if a molecule has no charge but it has a double or triple bond: break the double/triple bond between atoms #1 and #2. place a lone pair and a negative charge on atom #1 and a positive charge on atom #2
- if the molecule has both a positive and negative charge adjacent: move the lone pair from atom #1 and make a double bond between atoms #1 and #2
