Chemistry: Modern Atomic Theory

Heat vs. temp

temperature - the average kinetic energy of particles within an object

heat - the flow of energy caused by a temperature difference (also more heat is if there are more particles at a high energy/temp)

more heat in bonfire than in match even if same temp

Types of energy

electrical, heat/thermal, light/radiant, nuclear, chemical, sound, magnetic, mechanical

Calorimetry calculations equation

q=mc(T2-T1)

q- heat joules

m - mass grams

c- specific heat j/g degrees Celsius

T-temperature degrees Celsius

Specific heat (capacity)

the heat required to raise a unit mass of a substance by one degree of temperature J/gºC.

high specific heat - good insulator

low specific heat - good conductor

Exothermic vs endothermic

Exo- releases energy; feels warm

Endo- absorbs energy; feels cold

Law of conservation of energy

energy cannot be neither created no destroyed, only transferred

Electromagnetic spectrum

(lowest frequency and energy) radio waves, microwaves, infrared radiation, visible light, ultra violate, x rays, gamma rays (highest)

Wavelengths of colors

Red- longest wavelength, lowest frequency, lowest energy

Orange, yellow, green, blue in between

Violet- shortest wavelength, highest frequency, highest energy

Light equation

E = hc/λ

h and c are constants e is energy and λ is wavelength

Quantization of energy

certain quantities of energy are moved when electrons change energy levels, and those numbers are specific and values between those that coordinate with specific changes between levels do not exist

Photoelectric effect

The experiment that proves that light behaves like particles sometimes, and not always like waves. When light is shown on a metal, electrons are ejected from the metal. This only happens of the light has enough energy. If light behaved only like a wave, this would only happen if the light is bright enough (amplitude). But, it behaves like particle sometimes, and frequency determines whether electrons are ejected or not (so energy is related to frequency, not amplitude).

Bright line emission spectra vs continuous spectrum

bright line means that only certain wavelengths of energy are created when electrons move between energy levels, which only releases certain colors, in comparison to continuous where there are all the possible wavelengths of energy getting released, therefore all the light colors can be seen
continuous only occurs because the sunlight energy is scattered by water droplets

Ground state vs. Excited state

Ground - when an electron is at the lowest energy level possible

Excited - when an electron has any more energy than the minimum level

Admission vs absorption of energy

Admission- releasing energy, producing light or heat

Absorption - absorbing energy, feeling cold to the touch

Energy levels / principal quantum levels

1s is 1st level. 2s is second level. 2p is still second level….etc. when an electron goes n=3 to n=1 then it drops two energy levels

Limitations on Bohr’s model

It only explained the phenomenon that occurred when there was only one electron (hydrogen atom). It couldn’t account for how different electrons interacted with each other so it fell short with all other atoms

DeBroglie’s ideas

1924 - proposed that all moving objects have wave properties (small particles)

E = mc² = hv = hc/λ = h/(mv)
mc=h/λ

Heisenberg’s ideas

created the uncertainty principle w cannot simultaneously know an electron’s momentum and position (we can define e-energy exactly but we won’t know exact position)

Schrödinger’s ideas

developed wave equation and stated that we can find the area of probability for an electron (orbital)

Orbital shapes model/diagrams

the diagrams with the weird bulbous shapes around the axis

s diagram - sphere

p diagram - dumbell

Aufbau principle

lowest energy orbitals are filled first

Hund’s rule

when orbitals of identical energy are avaliable, electrons enter these orbitals singly before any spin pairing takes place.

Pauli exclusion principle/model

orbitals can only contain a maximum of two electrons and when two electrons enter the same orbital, they must have opposite spin (never up up or down down)

noble gas configurations

find the nearest noble gas that is before the element, then list the gas and the electron configuration from the gas to the needed element

Ex: Bi : [Xe] 6s² 4f¹⁴ 5d¹⁰ 6p³

sublevels in electron configurations

s - located to the most left on table (incl. H) and leading number is the row number (1s²)
p - located to the most right on the table and leading number is row number (2p⁶)
d - located in middle and leading number is one less than row number (3d¹⁰)
f - located below and leading number is two less than row number (4f¹⁴)

what lambda symbolizes (λ)

wavelength

Planck

defined relationship between energy and frequency

E = h v, where e is energy, h is a constant, and v is frequency

what nu symbolizes (V)

frequency

what E symbolizes

energy

definition of when something is quantized

restricted to specific boundaries or energy level

available in discreet amounts - single values

orbital diagram

diagram with the boxes and the arrows that shows the sub-levels

on bohrs model, what can you see what can’t you see (obvi just for hydrogen)

can see (VL) - changes that result in n=2

can’t see (prolly UV) - changes that result in n=1