Atomic Structure 4

What is an emission spectrum

A series of discrete lines produced by excited atoms

What gas is commonly used in emission spectrum experiments

Hydrogen gas

What happens when electricity passes through hydrogen

It emits light

What is observed through a prism

Discrete bright lines on dark background

Why are lines discrete

Electrons transition between fixed energy levels

What does each spectral line represent

Specific wavelength or frequency

What causes emission of light

Electron dropping to lower energy level

What determines energy of emitted photon

Difference between energy levels

What is formula for photon energy

E = hv

What does h represent

Planck’s constant

What does v represent

Frequency

What is Lyman series

Transitions to n=1

Region of Lyman series

Ultraviolet

What is Balmer series

Transitions to n=2

Region of Balmer series

Visible light

What is Paschen series

Transitions to n=3

Region of Paschen series

Infrared

What wavelength range is visible spectrum

400 to 700 nm

What wavelength is less than 400 nm

Ultraviolet

What wavelength is greater than 700 nm

Infrared

What does shorter wavelength mean

Higher energy

What does longer wavelength mean

Lower energy

What is the significance of emission spectrum

Evidence for discrete energy levels

What theory explains emission spectrum

Bohr model

Why Rutherford model failed

Could not explain line spectra

Another flaw of Rutherford model

Electrons should spiral into nucleus

Why electrons would spiral

They lose energy as radiation

Why atoms are stable

Rutherford model incomplete

How did Bohr fix Rutherford model

Introduced quantized orbits

What are quantized orbits

Fixed energy levels for electrons

What happens in stable orbit

Electron does not radiate energy

When is radiation emitted

When electron jumps levels

What is ground state

Lowest energy level

What is excited state

Higher energy level

What happens when electron absorbs energy

Moves to higher level

What happens when electron emits energy

Drops to lower level

What determines orbit size

Energy of electron

Which orbit has lowest energy

Closest to nucleus

Which orbit has highest energy

Farthest from nucleus

Why Bohr model works for hydrogen

Single electron system

Limitation of Bohr model

Does not work well for multi-electron atoms

What is wave particle duality

Light behaves as both wave and particle

What is electromagnetic radiation

Energy traveling as waves

What are components of EM waves

Oscillating electric and magnetic fields

Speed of light value

3.0 x 10^8 m/s

What is frequency

Number of waves per second

What is wavelength

Distance between wave peaks

Relationship between wavelength and frequency

Inverse relationship

Formula linking them

c = λv

What is Planck’s theory

Energy emitted in discrete packets

What is a quantum

Smallest packet of energy

What did Planck explain

Blackbody radiation

What is photon

A particle of light energy

Energy of photon depends on

Frequency

Higher frequency means

Higher energy photon

What is ionization energy

Energy needed to remove electron

What happens at ionization limit

Electron leaves atom

What is convergence limit

Lines get closer at high energy levels

What happens as n increases

Energy levels get closer

Why spectral lines converge

Energy differences decrease

What is continuous spectrum

All wavelengths present

What is line spectrum

Only specific wavelengths present

Why hydrogen spectrum important

Shows quantized energy levels

What produces blue light in experiment

Excited hydrogen atoms

What tool separates light

Prism

What is diffraction

Spreading of waves

What is interference

Overlapping waves

What is absorption spectrum

Dark lines on continuous spectrum

What causes absorption spectrum

Electrons absorb specific wavelengths

What is significance of absorption

Confirms energy levels

What happens when atom absorbs photon

Electron jumps to higher level

What determines color of light

Wavelength

Short wavelength color

Violet/blue

Long wavelength color

Red

What is series limit

Maximum energy transition

What is quantum number n

Energy level index

Lowest energy level

n=1

What is electron transition

Movement between energy levels

What does emission confirm

Atomic structure

What is main conclusion from spectra

Energy levels are discrete

What does Bohr model explain successfully

Hydrogen spectrum

What concept replaced Bohr model

Quantum mechanics

Why is Bohr still important

Foundation for modern atomic theory