Atomic structure and interatomic bonding Chpt 2 Flashcards
What is the net force
sum of attractive and repulsive forces
What do the attractive force depend on
depends on type if bonding that exists
What causes repulsive forces?
when negatively charged electron clouds interact with small distances and when outer electron shells overlap
When does further pushing or pulling from atoms prevented by attractive and repulsive forces
.3nm
What are the primary and secondary bonding forces
ionic, covalent and metallic
van der waals
What subatomic particle has a smaller massq
electorn
Where is the atomic number located?
atomic mass?
bottom left
top left
Explain carbon-15
number of carbon is 12 but has 3 neutrons
Unit for atmoic mass. how is it defined
amu
1/12 of atomic mass of most common isotope carbon atom (6protons 6 neutrons
Whatis the z number?
protons
Whats bhors atomic model
think rings n=3 etc
electrons in orbitals
What is the wave-mechanical model?QAs`
tells us that electrons move in fuzzy orbits, not circular
Can only tell you probability of finding them at various locations around the nucleus
electrons considered to have wave and particle like characteristics
What is the Quantum-mechanical principle
Energies of electrons are quantized
principles that govern sys of atomic and subatomic entities
What are subatomic particle charges measured in
Coulombs
attractive bonding forces are coulombic
Charge of pr and el
1.602 x 10^-19C
What letter is the atomic number
Z
Atomic mass vs atomic mass unit vs atomic weight
atomic mass: neutrons v protons
1/12 of atomic mass of most common carbon isotope carbon-12
average weight of the atom’s isotopes
What letter is atomic mass
A
mole is?
6.022 x 10^23
1amu/atom(or molecule) = 1g/mole
Can electrons have different energies?
YES! they can change energy orbitals and have different energies in different moments
Pauli exclusion principle
No two electons in same atom have identical values for all four of their quantum numbers
electron configuration
Describe all four quantum numbers
Principle Quantum Number (n): tells you the energy level of an electron inside an atom (size of electron orbital)
Angular Momentum Quantum Number (l): describes the shape of the sublevel within an energy level
s (shere) - 0 has one orbital
p (3D infinity) - 1 has 3 orbitals
d (4 flat bubbles) - 2 has 5 orbitals
f (two bubles as axis) - 3 has 7 orbitals
Magnetic Quantum Number (m_l): describes orbital within sublevel
-l <= m_l <= l
Electron Spin (m_s): can be +1/2 or -1/2
an electron in an orbital can either go up or
down
ex: 3d^8 is a -1/2 or +1/2 depending on if
you start with all down or up arrows
https://www.youtube.com/watch?v=eRIN9CPDrpo
Whats ground state
the lowest energy an atom can be in
Are noble gases reactive or unreactive
unreactive
name the column names
8th: noble (inert) gases
7th: halogens
4-6: other nonmetals (including hydrogen)
3rd: metalliods ( horizontal pattern)
between 2 and 3: transition metals
2nd: alkaline earth metals
1st: alkali metals
study periodic table
upper low: lanthanides
lower low: actinides
describe the periodic table trend with spdf
Electropositive vs electronegative and periodic trend
+: willing to give up electron
-: readily accept electrons
more electronegative as you move to the right of P.T.
Ionic vs covalent bonding
metal and nonmetal bonding (transferring electrons requires large electronegative difference nondirectional bond. dissolve in water easily and other polar solvents. Tend to form crystalline solids with high melting temperature
between atoms of small electronegative differences (near in periodic table). orbital overlap. Highly directional bonding bc they bond in the direction of greatest orbital overlap (diamonds, polymeric molecules like ethylene, ceramics and semi-conductors)
Where do electrons go when they have more energy?
higher orbital
What does the group number tell you about an atom
the number of electrons available
when atoms are at r0?
atom is in equillibrium
Whats bonding energy E_o?
amount of energy required to break a mole of molecules into component atoms
Equilibrium is reached in forces when bonding energy is minimized
cation vs anion
cation (+)
anion (-)
What are nondirectional bonds
when the direction of the attraction between atoms do not matter.
Why do electrons transrer in ionic bonding?
atoms want to be at a ground state level, meaning they want to reduce the energy of the system.
how do you name an ionic compound
name the metal first, then the nonmetal second
What is mtallic Bonding?
valence electrons detached from atoms and swim in electron sea that glues ions together.
Non-directional bonding
metal is held together by strong force of attraction between positive nuclei and delocalized electrons
What is non-directional bonding
probability of sharing electron is equal in all directions
What happens to nuclei when valence elctron are in elecytorn sea?
nucleus and core electrons for ion cores with net positive charge,
what are delocalized electrons
valence electrons that don’t belong to any one atom.
What is the van de Waals
weak attractive force between dipoles
like when sodium chloride positive side attracts negative other atom
secondary attractive
what are dipoles
pair of electric charges or magnetic poles of equal but opposite charge, separated by small distance
Whats permanent dipole?
like when sodium chloride positive side attracts negative other atom
all due to asymmetrical arrangment of positive and negative regions
strongest secondary bond
How do polar molecules affect nonpolar molecules?
makes them polar, lol
bond is formed due to attraction between permanent and induced dipoles
can electrically symmetric molecules and atoms create a dipole
yes. fluctiations in electron density (fluctuating dipoles)
weakest bond
what bonding in each material?
metals
ceramics
polymers
semiconductors
metallic
ionic/covalent
covalent and secondary
covalent or covalent/ionic
periodic trend for atomic size, electronegativity, ionization
calculate the ionic percentage of materials
IC% = {1-exp(-(0.25)(X_A-X_B)^2)}*100
X_A and X_B are the electronegativity of the elements in the materials
table for bonding energies and melting temperatures
look at last slide of week 3
