Ch 4 | Electrons in Atoms

3 properties of waves

wavelength, frequency, and amplitude

frequency

measure of how many waves pass a given point in a specific amount of time; measured in Hz or cycles per second; greek letter > 𝝂

wavelength

measure of the distance from 2 similar points on a wave; measured in length(m or nm); greek letter > λ

amplititude

measure of the distance between a line through the middle of a wave and the highest/lowest point of it

parts of a wave

crest - highest point & trough - lowest point

one cycle of a wave is

one up and down

the higher the amplitude means

the higher the wave, the louder the sound, and the brighter the light

speed of all forms of electromagnetic radiation/waves

3.0 x 10^8 m/s

electromagnetic spectrum

all the forms of electromagnetic radiation

gamma rays vs radio waves

frequency: gamma rays largest & radio waves smallest

energy: gamma rays largest & radio waves smallest

wavelength: radio waves largest & gamma rays smallest

ROYGBIV

what white light separates into; red light has the larger wavelength and smaller frequency

how are wavelength and frequency related?

INDIRECTLY; as λ increases, 𝝂 decreases

how are frequency and energy related?

directly, as 𝝂 increases, E increases

calculations for λ, 𝝂, and E

Planck's constant

6.626 x 10^-34

as energy increases

frequency increases and wavelength decreases

atomic spectrum/bright line spectrum

when energy is added to an element in gas phase; it glows one color when see through a prism; result of emission/ energy changes of electrons

absorption

when electrons gain energy; electron goes away from nucleus

emission

when electrons lose/give off energy; electron goes toward nucleus

# of orbitals on energy level

n^2

# of electrons that can fill an energy level

2n^2

# of sublevels of an energy level

n

sublevels

subdivisions of energy levels > s (1 orbital), p(3), d(5), f(7)

spacing in energy levels

no evenly spaced; most space between 1S and 2S; get closer as you go up; higher energy levels are away from nucleus

ground vs excited state

ground - lowest energy state; excited - higher potential energy

quantum of energy

the minimum quantity of energy that can be lost or gained by an atom

quantum numbers

specify the properties of atomic orbitals and the properties of electrons in orbitals

principal quantum number

symbolized by n, indicates the main energy level occupied by the electron; roughly determines the size

angular momentum quantum number

symbolized by l, indicates the shape of the orbital

magnetic quantum number

symbolized by m, indicates the orientation of an orbital around the nucleus

spin quantum number

has only two possible values (+1/2, -1/2) which indicate the two fundamental spin states of an electron in an orbital; symbolized by m_l

Aufbau Principle

An electron occupies the lowest-energy orbital that can receive it

pauli exclusion principle

electrons in the same orbital will have opposite spins

hund's rule

orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin; to avoid electron repulsion

HOEL (highest occupied energy level)

the energy level with the highest value of n; contains orbitals furthest away from the nucleus

Outer shell

orbitals in the HOEL

Valence electrons

electrons found in the HOEL; furthest away from nucleus

Core electrons

electrons closest to the nucleus

Inner shell

orbitals that contain the core electrons

electron configuration

organization of electrons in atoms from orbitals of lowest energy to orbitals of highest energy

exceptions for electron configuration

half filled or half/full to avoid electron repulsion or make it more stable

energy level

distinct region where electrons in an atom occupy/are found

orbitals

indicates probable location of an electron; holds 2

electron configurations for ions

anions-add electrons

cations-remove valence electrons

s orbital shape

sphere

p orbital shape

double lobed