Transcript The Bohr Model of the Atom

The Bohr Model of the Atom
DO NOT WRITE ON THESE NOTES
COPY THESE NOTES IN CORNELL
STYLE IN YOURBINDER.
What do we need to know?
• Atoms have 2 main parts
– Electron cloud -- contains electrons
– Nucleus – central part of the atom, contains
protons and neutrons
Subatomic particles
• Symbols for each subatomic particle
– Electrons = e– Protons = p+
– Neutrons = n0
(found in the electron cloud)
(found in the nucleus)
(found in the nucleus)
What do you need to know?
• Orbitals are found around
the nucleus
Period 1
– There are 7 possible
orbitals
Period 2
– Orbitals are determined by
looking at what PERIOD
(row) the element is in
Period 5
– The orbitals hold a specific
number of electrons (which
is the same as the atomic
number)
Period 3
Period 4
Period 6
Period 7
How many electrons per orbital?
Period 1 
orbital (ring) 1: 2 e-
Period 2 
orbital (ring) 1: 2 eorbital (ring) 2: 8 e-
Period 3 
orbital (ring) 1: 2 eorbital (ring) 2: 8 eorbital (ring) 3: 8 e-
Period 4 
orbital (ring) 1: 2 eorbital (ring) 2: 8 eorbital (ring) 3: 18 eorbital (ring) 4: 8 e-
Information to create a Bohr model
Atomic # = Protons and Electrons
• Element name and symbol:
–
–
–
–
–
–
Magnesium (Mg)
Atomic number: 12
Atomic mass: 24
Protons: 12
Electrons: 12
Neutrons: (24 - 12) = 12
Atomic Mass – Atomic # = Neutrons
Atomic Mass
12
Mg
24.305
Magnesium
Orbital 3 can
only hold a
maximum of 8
electrons, but
you only use
the # of
electrons you
need.
Bohr model for Mg
Magnesium will
have 3 orbitals
because it is in
period #3
Electrons are
represented by the
dots.
Nucleus
Orbital 2
can only
hold a
maximum
of 8
electrons
When you add all
the dots
(electrons) you
should get 12.
12p+
12n0
Orbital 1
can only
hold a
maximum
of 2
electrons
Bohr model for Al
• Aluminum is in period #3 and has 13
electrons.
13p+
14n0
Your Assignment!
This goes on a separate piece of paper!
• Create the Bohr model for elements 1-20 on the
periodic table. (Hydrogen (H) – Calcium (Ca))
• For each element provide the:
–
–
–
–
–
–
Write the element name: __________________
Protons= ____
Electrons= ____
Neutrons= ____
Period = _____ = Orbitals= _____
Bohr Model: