VDLHS Honors Chemistry Unit 2

Links for practice

Coulumb’s Law

F= k(q₁)(q₂) / r²

Quantum Mechanical Model

Electrons most likely found in energy levels, sublevels, and atomic orbitals. Electrons further from nucleus feel less attractive force and generally have more energy

Sublevel

Region found in energy level where e is likely to be found (s,p,d,f)

Orbital

Region in sublevel were e^- is most likely to be found

Orbital shape

Orbitals overlap on top of each other to create sublevels, sublevels overlap on top of each other to create energy levels. Altogether, these orbitals, sublevels, and energy levels create the electron cloud. Electrons move between energy by absorption.

S sublevel

Shape=spheres; first present - n=1; orbital = 1; each orbital can hold 2e^-

P sublevel

Shape=dumbbells; first present- n=2; orbitals=3(px, py, p²)'; each orbital can hold 2e^-, total = 6e^-

D sublevel

Shape=flower-ish; first present - n=3; orbitals = 5; Each orbital can hold 2e^-, total=10e^-

F sublevel

Shape-wild; first present - n=4; orbitals=7; each orbital can hold 2e^-, total=14e^-

Aufbau Principle

Electrons occupy the lowest energy level(s), subleve(s), and orbital(s) first; like the Bohr model, we must build the electron cloud from the ground up.

Hund’s Rule

When electrons occupy orbitals from the ground up energy, they don’t pair up until they have to minimize electron - electron repulsion

Pauli Exclusion

There are two electrons at most per orbital; these electrons must have opposite signs

Electrons with the highest principle quantum number

How do you find valence electrons?

1s²2s²2p⁶3s²3p⁶4s²3d³

Electron configuration for Vandium

Effective Nuclear Charge (Z^eff)

Total positive charge felt by valence electrons = p^+ - inner e^-

Shielding

An increase in distance between nucleus + valence electrons that results in a decrease in attractive force

Atomic Radius

Distance from nucleus of a neutral atom to its outermost electron

If they have a larger core charge or attraction (Coulomb’s law)

How do you know if an element has a smaller atomic radius? (Smaller distance from core is good)

Particle changes

What is q1 and q2 in Coulomb’s Law?

Distance between particles

What is r in Coulomb’s Law?

First ionization energy

Amount of energy to remove the first electron from the valence energy level of an atom

Be, lower, charge, lower, distance

Which has a lower first ionization rate: Be or N?

_____ has a lower first ionization energy because according to Coulomb’s Law, it has a (higher/lower) attractive force because its ____ is (higher/lower), and _____ is irrelevant here.

Electronegativity

The ability of an atom to attract an outside electron (opposite of first ionization?)

F, higher, charge, higher, distance

Which has a higher electronegativity: C or F?

__, because according to Coulomb’s law, it has a (higher/lower) attractive force since its __ is (higher/lower), and __ is irrelevant here

NO, n/a

What are the electronegativities of Noble Gasses?

higher stability

Full valence energy level = ____

A higher attractive force

If something has a higher charge and lower distance, then they have a (higher/lower) _____

higher, higher

If something has a higher attractive force, then they have a (higher/lower) first ionization and a (higher/lower) electronegativity

They want to keep as many valence electrons in as possible, so they’re more “reluctant” to let them go

If something has a higher attractive force, WHY do they have a HIGHER first ionization rate?

nearly

Half-filled sublevels are ____ as stable as full sublevels

Emmission Spectroscopy

Experiment technique that shows what happens when excited electrons fall back down to lower energy levels

Emission spectrum

Shows which colors are emitted when excited electrons fall, like the elements’ fingerprints

Ground state

Electrons in their expected energy level

Excited state

Electrons in higher energy levels

False, we see it when they fall back down to ground states

True or false: We see color during emission spectroscopy when electrons specifically jump up to excited states

Radiation

Emission of energy

ground, excited, radiation

Electrons are mobile, so when they go to their ___ state from their ____ state we observe ______

Wavelength (λ)

distance between identical points on a wave

Wavelength unit

meters or nanometers (1 nm = 1 × 10^-9) ; always convert to meters in calculations!

Frequency (v)

the number of waves that pass a given point in one second

Frequency unit

Hertz = Hz = 1/s = s^-1

Wavelength and frequency

c=λv

c

speed of light in a vaccum = 3.00 × 10⁸ m/s

Energy of the photon

E=hv

Units for energy

Joules or J

h

Planck’s constant = 6.626 × 10^-34

lower, less

When there’s a longer wavelength, there’s a ____ frequency, and therefore ___ energy

Balmer

Transition to a less excited state

more

The bigger the jump down, the ___ energy is released

red

n=3 —> n=2

green

n=4 —> n=2

blue

n=5 —> n=2

dark violet

n=6 —> n=2