What can happen when an atom absorbs energy? 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

agreed with Rutherford’s model but added something to it 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

when it loses the energy it emits it as light 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)

Electron Cloud Model of a Hydrogen Atom 4.3 Modern Atomic Theory Electron Cloud Model of a Hydrogen Atom

4.3 Modern Atomic Theory

orbital – region of space where an electron is likely to be found 4.3 Modern Atomic Theory orbital – region of space where an electron is likely to be found

Energy Level, Orbitals, and Electrons 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 2 4 8 3 9 18 16 32

atoms emit light when their electrons return to ground state 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

electron configuration energy levels Chapter 4 Vocabulary isotopes proton nucleus mass number electron configuration energy levels atomic number neutron orbital electron cloud electron ground state excited state

isotopes proton nucleus mass number energy levels atomic number Chapter 4 Vocabulary isotopes proton nucleus mass number energy levels atomic number neutron orbital electron cloud electron ground state excited state

isotopes proton mass number energy levels atomic number neutron Chapter 4 Vocabulary isotopes proton mass number energy levels atomic number neutron orbital electron cloud electron ground state excited state

isotopes proton mass number energy levels atomic number orbital Chapter 4 Vocabulary isotopes proton mass number energy levels atomic number orbital electron cloud electron ground state excited state

isotopes proton mass number energy levels atomic number electron cloud Chapter 4 Vocabulary isotopes proton mass number energy levels atomic number electron cloud electron ground state excited state

isotopes proton mass number energy levels atomic number electron cloud Chapter 4 Vocabulary isotopes proton mass number energy levels atomic number electron cloud electron ground state

isotopes proton mass number energy levels electron cloud electron Chapter 4 Vocabulary isotopes proton mass number energy levels electron cloud electron ground state

proton mass number energy levels electron cloud electron ground state Chapter 4 Vocabulary proton mass number energy levels electron cloud electron ground state

proton mass number 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