1. A New Atomic Model
Chapter 4
Section 1

2. Problems with Rutherford’s Model
Did not explain where the __________ were specifically arranged
Did not explain why the ___________ charged ________ did not get drawn into the positively charged __________
How could the positively charged protons be ___________________in the nucleus?

3. The Wave Description of Light
_________________________: a form of energy that exhibits wavelike behavior as it travels through space
__________is a form of electromagnetic radiation
______________________: all the forms of ________________________

4. More Facts about Light
Light travels at ______________ through a vacuum
____________: (λ) is the _______ between corresponding points on adjacent waves
Units like _________ or ______________ etc.
_________: (ν) is the number of waves that pass a given point in a specific time
Measured in waves/s (cycles / sec or just sec-1)which is called a __________(Hz)

5. Wave (a) has a ___________ wavelength and a _________frequency than wave (b). They are ____________related.

6. The Photoelectric Effect
____________________: the emission of electrons from a metal when light shines on the metal
The ___________ of the light striking the metal must have a certain ___________ __________or no electrons were emitted, even if the light was very bright or shown on it for a long time.

7. More about Light
The wave theory of light predicted that light of _______________would supply enough energy to eject an __________ from the metal
_________, a German physicist, proposed that light must travel in _____________(packets; photons) of energy
Albert Einstein expanded on this theory by introducing the ____________________theory

8. The Wave- Particle Description of Light
________: the minimum quantity of ______ that can be lost or gained by an atom
__________: a particle of ____________ radiation having zero ______and carrying a quantum of __________
The energy of a particular photon depends on the _________of the radiation. They are __________related.

10. Visual of Photoelectric Effect
Electrons in different metals require _________________________________ to exhibit the photoelectric effect.

11. Ground State vs. Excited State
___________: the lowest energy state of an atom
________: a state in which the atom has a _________ potential energy than it has in the ground state
Excited atoms will return to the _______ ________upon losing the proper amount of ____________.
Only one ground state for an atom, many excited states

12. Radiant Energy Spectrum
The complete radiant energy spectrum is an uninterrupted band, or _____________________.
The radiant energy spectrum includes most types of radiation, most of which are invisible to the human eye.

13. Visible Spectrum
_____________ usually refers to radiant energy that is visible to the human eye.
The _________________________is the range of wavelengths between 400 and 700 nm.
Radiant energy that has a wavelength lower than 400 nm and greater than 700 nm cannot be seen by the human eye.

14. Emission-Line Spectrum
When an atom returns to its ground state, it emits _________________
__________________: a diagram or graph that indicates the degree to which a substance emits radiant energy with respect to wavelength; shows the type of ________________(“color”).

15. Hydrogen Atom Emission-Line Spectrum
An _______current is passed through __ at low pressure
There was a _________ light emitted
When the light was passed through a prism, it was separated into ________ colors of ___________.
This was the _____________________.

16. Emission Line Spectra
When an electrical voltage is passed across a gas in a sealed tube, a series of narrow lines is seen.
These lines are the _________________________. The emission line spectrum for hydrogen gas shows three lines: 434 nm, 486 nm, and 656 nm.

17. More about Hydrogen
There were other series of lines in the UV and IR regions of hydrogen’s emission-line spectrum
The series are called Lyman (UV), Balmer(visible), and Paschen (IR) after their discoverers

18. The Bohr Model _____________was a Danish physicist.
He linked the atom’s electron _______to ___________________.
According to his model, the electrons can circle the nucleus only in __________ allowed paths, or _________.
The electron is in its ___________energy state (ground state) when it is closest to the _______________.
Hydrogen only has one electron

19. Electrons Around the Nucleus
The orbit is separated from the nucleus by an _________space where the electron __________exist.
When the atom is in the _________state, the electron is in a ________orbit farther from the nucleus.
There are only ________orbits available, like the rungs of a ladder.

20. Evidence for Energy Levels
Bohr realized that this was the evidence he needed to prove his theory.
The electric charge temporarily excites an electron to a higher orbit. When the electron drops back down, a photon is given off.
The red line is the least energetic and corresponds to an electron dropping from energy level to energy level 2.

21. Energy must be added to the atom to move an electron to a higher level
Energy must be added to the atom to move an electron to a higher level. This is called ____________.
When a hydrogen atom is in an _______ state, the electron is in a ________orbit.
When the atom returns to the ground state, it emits energy in the form of a photon. This is called ______________.

22. More about Bohr’s Model
Bohr related the possible energy-level changes to the lines in the hydrogen emission-line spectrum
He calculated mathematically values for the lines
Unfortunately, Bohr’s model did not explain the emission-line spectrum of atoms with _______________________.

23. Emission-Line Spectra
The emission spectrum of each element is ____________.
Emission spectra can be used to ______ __________________.
Also used to determine the relative composition of stars

24. “Fingerprints”- Emission-Line Spectra