Transcript 4.3 Modern Atomic Theory

4.3 Modern Atomic Theory
What can happen when an atom absorbs energy?
- an increase in kinetic energy or a phase change
energy may be
absorbed by an
atom, then emitted
as light
4.3 Modern Atomic Theory
Niels Bohr (1885-1962)
agreed with Rutherford’s model but
added something to it
energy levels – the possible energies that electrons in an
atom can have
4.3 Modern Atomic Theory
when an atom gains energy an electron may move to a
higher energy level
when it loses the energy
it emits it as light
no two elements have the same set of energy levels, so the
emit different colors of light
4.3 Modern Atomic Theory
Electron Cloud Model
electron cloud model – model of the most likely locations for
electrons in an atom (deals with probability)
4.3 Modern Atomic Theory
Electron Cloud Model of a Hydrogen Atom
4.3 Modern Atomic Theory
4.3 Modern Atomic Theory
orbital – region of space where an electron is likely to be found
4.3 Modern Atomic Theory
electron cloud – a good approximation of how electrons
behave in their orbitals
Energy Level, Orbitals, and Electrons
Energy Level
Number of
Orbitals
Maximum # of
Electrons
1
1
2
2
4
8
3
9
18
4
16
32
4.3 Modern Atomic Theory
electron configuration – arrangement of electrons in the
orbital of an atom
ground state – electrons are all in their lowest possible
energy levels (most stable)
excited state – one or more electrons are in a higher energy
level than usual (least stable)
atoms emit light when their
electrons return to ground
state
Chapter 4 Vocabulary
isotopes
proton
nucleus
mass number
electron configuration
energy levels
atomic number
neutron
orbital
electron cloud
electron
excited state
ground state
Chapter 4 Vocabulary
isotopes
proton
nucleus
mass number
energy levels
atomic number
neutron
orbital
electron cloud
electron
excited state
ground state
Chapter 4 Vocabulary
isotopes
proton
mass number
energy levels
atomic number
neutron
orbital
electron cloud
electron
excited state
ground state
Chapter 4 Vocabulary
isotopes
proton
mass number
energy levels
atomic number
orbital
electron cloud
electron
excited state
ground state
Chapter 4 Vocabulary
isotopes
proton
mass number
energy levels
atomic number
electron cloud
electron
excited state
ground state
Chapter 4 Vocabulary
isotopes
proton
mass number
energy levels
atomic number
electron cloud
electron
ground state
Chapter 4 Vocabulary
isotopes
proton
mass number
energy levels
electron cloud
electron
ground state
Chapter 4 Vocabulary
proton
mass number
energy levels
electron cloud
electron
ground state
Chapter 4 Vocabulary
proton
mass number
electron cloud
electron
ground state
Chapter 4 Vocabulary
proton
electron cloud
electron
ground state
Chapter 4 Vocabulary
proton
electron
ground state
Chapter 4 Vocabulary
proton
electron
Chapter 4 Vocabulary
proton
Chapter 4 Vocabulary