Transcript What is the atomic

1. Explain why each of the following models
was developed:
Day 1
plum pudding
11-22
Rutherford’s
Bohr’s
electron cloud
Day 1
11-22
What does the inside of an
atom look like and how do we know?
Day 1 11-22
Atomic number = protons = electrons
(neutral atom)
Mass # = Atomic # + neutrons
Parts of Atoms, Isotopes, and
Ions
• Ions
–________
Charged atoms that have gained
electrons
or lost ________
–Examples
• Iron loses 2 electrons
+2
Fe
• Chlorine gains 1 electron
-1
Cl
Parts of Atoms, Isotopes, and
Ions
Fundamental parts of atoms
APPROXIMATE LOCATION
CHARGE
COMPONENT
MASS (in amu) IN ATOM
electron
-1
0.00055
shells
proton
+1
1.0
nucleus
neutron
0
1.00055
nucleus
Parts of Atoms, Isotopes, + Ions
atom of any element
–Individual _____
nuclear
–Represented with a _______
symbol
A
C
• X = _______
element _______
symbol
mass _______
number
• A = ____
Z
• Z = ______
atomic _______
number
X
Parts of Atoms, Isotopes, and
Ions
• X = _______
element _______
symbol
mass _______
number
• A = ____
• Z = ______
atomic _______
number
protons _______
number
= ______
• C = ______
charge __
as __
an ___
ion
Z
A - ___
• # neutrons = ___
Z - ___
C
• # electrons = ___
A
C
X
Z
Parts of Atoms, Isotopes, and
Ions
Mass number?
Atomic number?
# of neutrons?
Element?
Charge?
# of electrons?
19
1-
X
9
Particles of Radioacty. + Nuc. Rxns.
• Nuclear Reactions
–What forces act in the atom?
nuclear force holds
• Strong
______ _______
protons
_______ together
nuclear force causes
•Weak
_____ _______
radioactivity
___________
–Natural radioactivity, radioactive
decay, or nuclear disintegration
is the spontaneous
___________ …
Particles of Radioacty. + Nuc. Rxns.
• Nuclear Reactions
–Natural radioactivity, radioactive
decay, or nuclear disintegration
is the spontaneous
___________ … ________
emission
of ________
radiation from an element
due to instability of the _______.
nucleus
Particles of Radioacty. + Nuc. Rxns.
• Nuclear Reactions
–Problems in nuclear stability
occur when there are too few
or too many ________.
neutrons
–All elements with an atomic
number greater than ___
83 are
radioactive.
Unit 3 Practice # 2
Assignment:
#s 26, 27, 30, 31 on page 119
Assignment # 1 Unit 3
MAKE UP WORK!!!
Day 2
11-23
1. Draw a nuclear symbol for an
element with 17 protons, 18 neutrons,
and 18 electrons
a. What element is it?
b. What is the atomic #?
c. What is the mass #?
d. What is the charge?
Strong Nuclear Force
Rutherford’s model
Bohr’s model Chadwick
Electron
Dalton
J.J. Thomson Plum pudding model
Nucleus
Democritus
Atom
Isotope
Mass number
Proton
Neutron
Atomic number
Ion
Energy level
Electron cloud
Empty space
Quark
Gold Foil Experiment
Unit 3 Practice # 2 – due
today (Wed. 11-23)
#s 26, 27, 30, 31 on page 119
– due Tuesday 11-22
Assignment # 1 Unit 3 –
due Monday 11-21
Day 2 11-23
• Notebooks
• Timelines
• Test
• M.P. Grades
1. Explain the parts of the model and
specifically what each part represents.
2. Explain how or why the model was
developed.
3. Explain what it represents well (its
strengths as a model).
4. Explain some of its limitations (its
weaknesses).
1. Explain the parts of the model and
specifically what each part represents.
2. Explain how or why the model was
developed.
3. Explain what it represents well (its
strengths as a model).
4. Explain some of
its limitations
(its weaknesses).
QUICK
TALK
Thomson
Bohr
Atom
Dalton
Proton
Plum Pudding model
Electron cloud
Neutron
Law of Definite
Proportions
Alchemists
Mendeleev
We have Atoms! - 1850’s
Cathode Ray Tubes
Parts of Atoms, Isotopes, and
Ions
Mass number?
Atomic number?
# of neutrons?
Element?
Charge?
# of electrons?
42
2+
X
20
11-16
1. Thomson’s model of the atom
was the first to show _________.
2. One thing that Thomson’s
model showed incorrectly or not
at all?
11-19
1. Rutherford and Soddy showed that
radioactivity produces new
________________.
2. What information can you obtain
from a nuclear symbol?
What is the last thing you have in your notes?
Particles of Radioacty. + Nuc. Rxns.
Particles of Radioactivity
SYM
TYPE
CHARGE
BOL
alpha
beta
gam
ma

4He +2
2

-1
0e
-1

0
ALIAS
PENING.
ABILITY
helium low: stopped
nucleus by paper
medium:
electron stopped by
clothes
light
energy
high: stopped
by thick lead
and concrete
Particles of Radioacty. + Nuc. Rxns.
Particles of Radioactivity
TYPE
SYM CHARG
BOL
E
positron
0e
+1
ALIAS
+1
positive
beta
proton
1H
+1
hydrogen
nucleus
neutron
1n
0
0
1
PENING.
ABILITY
shortlived
Particles of Radioacty. + Nuc. Rxns.
• Nuclear Reactions
–The beta () particle has a
________
negative charge. How can it be
released from the nucleus?
A neutron splits into a proton and an elec.!
1n
0
→
1p+
1
0
–
+ - 1e