Transcript Ch 4

Ch 4
ATOMIC
STRUCTURE
All about the ATOM
The Structure of Atom’s
Subatomic Particles
Particle
Symbol Charge Location
Electron
e-
-
Around
nucleus
Proton
p+
+
Inside
nucleus
Neutron
n0
0
Inside
nucleus
Electrons are TINY compared to a Proton or Neutron
All elements are on the periodic
table of elements!
GET OUT YOUR
PERIODIC TABLE
REFERENCE SHEET
1
H
Atomic Number is # of p+ & ein atom
Atomic Mass # is average of
1.0079
all of isotopes of atom
(decimals)
round
1.0079
to 1,
1 is
mass #
Mass number (atomic mass
rounded)is sum of the p+ &
nO in atom
9
A
P
E
M
A N
F
To find # of p+, use Atomic #
18.988
To find # of e-, use Atomic #
0
n=
p+=
e=
To find # of no, subtract
Atomic # from Mass #
(round & subtract)
16
____________
Mass # =__________
Mass # = ___________
Mass # = ____________
Isotopes have same atomic # but
different mass # b/c they have
different #s of neutrons
Isotope
Carbon-11
Carbon-12
Carbon-13
Protons
6
6
6
Neutrons
5
6
7
Different ways to write isotopes:
12 C,
Carbon-12,
C-12
6
Atomic #
Mass #
Sample chart
Atom
Carbon-14
Boron
Boron-10
Mass# Atomic # p+
o
n
e-
Neils Bohr
• model stated e- move w/
constant speed in fixed
orbits around the
nucleus, like planets
orbiting the sun
Bohr
Model
• The possible energies e- in
atom can have are called
energy level (orbital, shell)
• e- in atom can move from
one energy level to another
when atom gains or loses e-
Atomic Orbitals & max e- in
each orbital
Energy
Level/Shell
Max # of
electrons
1
2
2
8
3
18
4
32
Practice drawing Bohr models
STAR Questions
• How many neutrons does Lithium have?
• How many electrons can go in the second
orbital?
• Draw a Bohr model of Al.