Download energy levels

Tuesday Oct 14
Objective: Describe different models of the atom.
Checkpoint:
• Draw a picture of a copper atom, including
electrons in the correct energy levels.
• Does copper want to gain or lose electrons to be
come stable? What ion will it form when it does
this to become stable?
HW:
• Study for Nuclear Chem re-take exam on
Wednesday (after school), 12:30 PM
• Read pp 104-108 in book (Section 4.2) Answer
questions 8-14 on pp 108. Due Friday.
Copper
29 p
35 n
Copper
29 p
35 n
Cu
2+
Nuclear Chem
make-up exam
Wednesday 12:30 PM
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Ba(NO3)2
Ca(NO3)2
Cu(NO3)2
Pb(NO3)2
LiNO3
KNO3
NaNO3
Sr(NO3)2
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Yellow/Green
Orange
Green/Blue
Light blue
Red
Pink/Purple
Bright yellow
Orange/Red
CuSO4
Cu(NO3)2
Cu
2+
Cu
Thomson Model
• Created the “Plum-pudding model”
• Electrons are surrounded by a sea of evenly distributed positive charge
9
Rutherford Model
• Small, dense, positive nucleus
surrounded by cloud of electrons
10
Bohr Model
• Proposed that electrons orbit the
nucleus in a fixed, circular path
• Orbit path has specific energy that
prevents electrons from falling into
the nucleus
• Quantum of energy is the amount of
energy needed to move an electron
between energy levels
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Bohr Model Picture
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Erwin Schrödinger
• Quantum Mechanical Model
– Modern model
– Estimates the probability of finding an
electron within a certain volume of space
surrounding the nucleus
– Where you find the electron 90% of the
time
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Electron Cloud Picture
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Energy Levels - 1
• Electrons exist within energy levels or
shells
– General location around the nucleus where
the electron is moving
– Energy levels are not equally spaced apart,
they become more tightly packed the farther
you get from the nucleus
15
Energy Levels - 2
• Principal quantum numbers (n) identify the
energy levels in an atom
– Tells you how far away the electron is from the
nucleus
– There are 1-7 energy levels, correlates with
period numbers
– Each level has same n number of sublevels
– Maximum number of 2n2 electrons per level
16
Atomic Orbitals - 1
• Atomic orbitals are more specific regions
within each energy level where electrons
are found
– Highest probability of finding an electron
– Also called sublevels, subshells, azimuthal
quantum number, or angular momentum
quantum number (l)
• Number of orbitals for each energy level
equals n2
17
Atomic Orbitals - 2
• Sublevels are designated by letters
– s,p,d,f
• Each sublevel has a unique shape and
number of orbitals related to different
spatial orientations
• Each sublevel orbital can hold a
maximum of 2 electrons
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Orbital Shapes
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Orbital Shapes cont.
Summary
• Each principal energy level consists of
one or more sublevels and each sublevel
consists of one or more orbitals
• Orbitals  Sublevels  Energy Level
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Thought of the Week
The joy of life comes from our encounters with new
experiences, and hence there is no greater joy than to
have an endlessly changing horizon, for each day to
have a new and different sun.
Christopher McCandless