chem unit 4 test

Light behaves as what TWO things? Wave + particle

Longer wavelength = MORE or LESS energy? LESS

Higher frequency = MORE or LESS energy? MORE

Wavelength UP → frequency? DOWN

EM spectrum: LOW to HIGH energy? Radio → Micro → IR → Visible → UV → X-ray → Gamma

Visible colors: LOW to HIGH energy? Red → Orange → Yellow → Green → Blue → Indigo → Violet

Electron jumps UP a level? ABSORBS energy

Electron falls DOWN a level? EMITS energy

When do you see colored light? When an electron emits visible light

Continuous spectrum looks like? Unbroken rainbow

Bright-line spectrum looks like? Separate colored lines

Why does each element have unique spectral lines? Different electron energy levels

Planck: energy comes in what? Packets called quanta

Why can violet light eject electrons but red may not? Violet photons have more energy

What did Bohr say about electrons? They occupy fixed energy levels

Heisenberg's Uncertainty Principle? Can't know exact position AND momentum

Bohr model: protons? Atomic number

Bohr model: neutrons? Mass number − atomic number

Neutral atom: number of electrons? Atomic number

First 3 Bohr shells (first 20 elements)? 2, 8, 8

Speed of light equation? c = λν

Find wavelength from frequency? λ = c / ν

Find frequency from wavelength? ν = c / λ

Find energy from frequency? E = hν

Find energy from wavelength? E = hc / λ

Convert nm to meters? Multiply by 10⁻⁹

What are c and h? c = 3.00 × 10⁸ m/s; h = 6.626 × 10⁻³⁴ J·s

Electron configuration tells you what? Where the electrons go

What does the big number in 3p mean? Principal energy level

What does the superscript in 3p⁴ mean? Number of electrons

How do you write a FULL configuration? Fill in order until electrons add to total

Max electrons in ONE orbital? 2

Max electrons in s, p, d, f sublevels? 2, 6, 10, 14

Number of orbitals in s, p, d, f? 1, 3, 5, 7

Filling order through 4p? 1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p

Aufbau principle? Lowest energy fills first

Hund's rule? SPREAD before pairing

Pauli exclusion principle? Paired arrows point opposite ways

Correct p⁴ orbital arrows? [↑↓][↑][↑]

Noble gas shorthand? Previous noble gas + remaining sublevels

Noble gases and electron counts? He 2, Ne 10, Ar 18, Kr 36, Xe 54

How do you find valence electrons? Add electrons with highest shell number

How do you identify an element from a configuration? Add superscripts → atomic number

Positive ion (+) does what? LOSES electrons

Negative ion (−) does what? GAINS electrons

Fe²⁺: which electrons leave first? 4s² → leaves [Ar] 3d⁶

Isoelectronic means what? Same electrons and configuration

For d-block, energy level number? Period number − 1

4s or 3d: which fills first? 4s

ONE f orbital vs. ENTIRE f sublevel? 2 vs. 14 electrons

Shapes of s, p, most d orbitals? Sphere, dumbbell, clover