Unit 3: Electron Structure

starts with photon notes and ends with lewis dot diagram notes

c =

v =

λ =

e =

h =

1. speed of light
2. frequency (s^-1 or Hz)
3. wavelength (meters)
4. energy of a photon
5. Planck’s constant

Speed of light equation?

3\.00 x 10^-8 m/s

Planck’s constant equation?

6\.626 x 10^-34 J S

1 meter = ? nanometers (nm)

10^9

1kHz = ? Hz

1000

Wavelength formula?

λ = c/v

Speed of light formula?

c = vλ

Frequency formula?

v = c/λ

Energy formulas?

1. e = hv
2. e = hc/λ

Bohr models are used to…

predict reactivity in elements

Valence Electrons

* electrons on the last energy level, look at them to determine reactivity.
* can be determined by looking at the top # of each column and taking the last # when there is two digits. (excluding 3-12)

What do you draw in the nucleus of a Bohr model?

\# of protons and # of neutrons (atomic # - mass # \[round decimal #\])

Rules for energy levels:

Level 1?

Level 2?

Level 3?

Level 4?

1. max. 2 electrons
2. max. 8 electrons
3. max. 18 electrons
4. max. 32 electrons

Group (family):

vertical column

Periods:

horizontal column

How many periods and groups are on the periodic table?

7 periods

18 numbered columns

3 types of elements?

1. metals
2. nonmetals
3. metaloids

Physical properties for metals:

* good electrical and heat conductors
* ductile - can be stretched into wire
* possess metallic luster
* solid at room temp (except for Hg)

Physical properties for non-metals:

* poor conductors of heat and electricity.
* nonductile
* do NOT possess metallic luster
* solids, liquids, or gases at room temp.

Chemical properties of metals:

* easily lose electrons
* form positive ions (cations)

Chemical properties of nonmetals:

* gain electrons
* form negative ions (anions)

Group 1 - Alkali Metals

* 1 valence electron (ns^1)
* form 1+ ion
* unusually soft
* very reactive
* stored under water
* reactivity increases from top to bottom of group

Group 2 - Alkaline Earth Metals

* 2 valence electrons
* form 2+ ions
* not as soft as group 1
* react more mildly.

Groups 3-12 - Transition metals:

* contain many everyday metals
* metal properties as listed earlier

Inner transition metals?

* Lanthanide (pd. 6)
* Actinides (pd. 7)
* rare in nature
* all solids
* similar properties across the period rather than down a group.

Group 17 - Halogens:

* nonmetals
* strong unpleasant odor and will burn flesh.
* doesn’t dissolve well in water.
* react with most metals and many nonmetals.

Group 18 - Noble Gases:

* not very reactive
* under normal conditions they do not form compounds with other elements.
* very stable

Shells

* an atoms energy levels.
* electrons can only exist on shells

To go up a level electrons must ____ __energy, and to go down a level, electrons must__ _____ energy.

absorb

release

Quantum:

the amt of energy needed to move electrons to another level.

What are the 4 types of electron orbitals?

s, p, d, f

How many electrons in each and how many orbitals?

s?

p?

d?

f?

s: 2 electrons, 1 orbital

p: 6 total, 2 electrons each, 3 orbitals

d: 10 total, 2 electrons each, 5 orbitals

f: 14 total, 2 electrons each, 7 orbitals

Aufbau principle:

fill in lowest available energy level 1st.

Pauli Exclusion Principle:

* each orbital can hold max of 2 electrons.
* electrons must spin in opposite directions.
* arrows represent electrons

Hund’s rule

spread out electrons within an energy sublevel before pairing them up.

Higher energy levels are _______ away from the nucleus.

farther

Effective nuclear charge:

the # of protons added for that period.

(+ and - electrons are attracted to each other)

Energy levels and shielding have an effect on what?

Group

Effective nuclear charge has an effect on what?

Period

Atomic size trends?

* increases going top → bottom
* decreases going left → right

Atomic size:

the distance between the center of the nucleus of an atom and its outermost shell

Atomic radius/Ionic:

Half the distance between the nuclei of two like atoms.

Atomic radius trends?

* increases going top → bottom
* decreases left → right

Ionization energy:

the amt of energy required to completely remove an electron from a gaseous atom.

What factors determine IE?

Period?

Family?

Period: the greater the effective nuclear charge, the greater IE.

Family:

* shielding effect
* greater distance from nucleus decreases IE.

Ionization Energy trends?

* first IE decreases going top → bottom.
* more shielding
* electron further from the attraction of nucleus.
* increases going left → right

What group has full orbitals/full octet?

noble gases

Atoms behave in ways to try and achieve what configuration?

noble gas.

Electronegativity:

* the tendency for an atom to attract electrons itself.
* an element with a big electronegativity means it pulls the electron towards itself strongly.

Electronegativity trends?

* increases going left → right
* metals at the left, let their electrons go easily = low electronegativity
* nonmetals want more electrons = high electronegativity
* decreases going top → bottom

What is the relationship between frequency and wavelength?

inversely proportional

What is the relationship between frequency and energy?

directly proportional

What is the relationship between energy and wavelength?

inversely proportional

inversely proportional

the relationship between two variables whose product is constant

Elements in the same (group / period) exhibit similar properties.

group

Elements in the same (group / period) have the same number of valence electrons.

group

Elements in the same (group / period) belong to the same energy level.

period

energy sublevel:

an orbital of a different shape, which describes where the electron is likely to be found

atomic orbital

a function describing the location and wave-like behavior of an electron in an atom

electron affinity

* the amt. of energy that is released when an electron is added to an atom.
* Halogens are the “hungriest” for electrons because they are only 1 away from having a full octet.

electron affinity, electronegativity, and ionization are all biggest where?

top right corner

If an element has more protons it has a smaller or larger radii?

smaller

If an element has less protons it has a smaller or larger radii?

larger

Higher energy levels are **closer/further** from the nucleus.

further

m → km conversion?

move decimal point 3 places left

km → m conversion?

move decimal point 3 places right

Niles Bohr

discovered that electrons orbit around the nucleus.

energy level (of an atom)

the energy an electron has that is above ground state.

photon

elementary particles with no charge, no resting mass, and travel at the speed of light

frequency (wave def.)

the # of waves that pass a fixed place in a given amt. of time.

Wavelength

the distance between any given point and the same point in the next wave cycle (m).

Dmitri Mendeleev

* wrote down the symbols for the chemical elements.
* put them in order according to atomic weight.

inert

a chemical substance that is not generally reactive.

electron configuration

the arrangement of electrons around the nucleus of a particular atom or molecule.

noble gas configuration

shortened method of writing the electron configuration.

Erwin Schrodinger

* discovered the wave equation, wave mechanics.


* discovered energy levels of electron

Charles Augustin de Coulomb

* invented torsion scales
* coulomb’s law predicts what is going to be the force of the electrostatic force of attraction between 2 forces.

Lewis Dot Diagram

diagrams that describe the chemical bonding between atoms in a molecule

2nd ionization energy

the energy required to remove the 2nd ion of an atom.

Marie Curie

* discovered radium and polonium
* found treatments for cancer