daily quiz. 1.where is the proton located? a.in the nucleus b.in a cloud around the nucleus c.both...
TRANSCRIPT
Daily Quiz
1. Where is the proton located?
A. In the nucleus
B. In a cloud around the nucleus
C. Both places
D. Nowhere
E. Different in different elements
Daily Quiz
2. What is the charge on an electron?
A. Positive
B. Negative
C. Zero
D. Changes with ionization
Daily Quiz
3. What is the mass of a neutron?
A. 1840 x the mass of a proton
B. 1/1840th the mass of a proton
C. Same as the mass of a proton
D. Zero
E. Changes with gravitation
Daily Quiz
4. J.J. Thompson measured the mass of the electron using a
A. balance beam scale
B. spring scale
C. sheet of gold foil
D. magnet
E. chocolate chip cookie
Daily Quiz
1. Where is the proton located?
A. In the nucleus
B. In a cloud around the nucleus
C. Both places
D. Nowhere
E. Different in different elements
Daily Quiz
1. Where is the proton located?
A. In the nucleus
B. In a cloud around the nucleus
C. Both places
D. Nowhere
E. Different in different elements
Daily Quiz
2. What is the charge on an electron?
A. Positive
B. Negative
C. Zero
D. Changes with ionization
Daily Quiz
2. What is the charge on an electron?
A. Positive
B. Negative
Daily Quiz
3. What is the mass of a neutron?
A. 1840 x the mass of a proton
B. 1/1840th the mass of a proton
C. Same as the mass of a proton
D. Zero
E. Changes with gravitation
Daily Quiz
3. What is the mass of a neutron?
A. 1840 x the mass of a proton
B. 1/1840th the mass of a proton
C. Same as the mass of a proton
D. Zero
E. Changes with gravitation
Daily Quiz
4. J.J. Thompson measured the mass of the electron using a
A. balance beam scale
B. spring scale
C. sheet of gold foil
D. magnet
E. chocolate chip cookie
Daily Quiz
4. J.J. Thompson measured the mass of the electron using a
A. balance beam scale
B. spring scale
C. sheet of gold foil
D. magnet
E. chocolate chip cookie
Daily Quiz
Homework
Page 104, problems 15, 16, 17, 21
What you will learn today:
•What do atomic number and atomic mass tell you?
•How do isotopes relate to atomic mass?
•How is an AMU defined? Why is it not exactly the mass of a proton or a neutron?
Hydrogen
1
H1.008
Hydrogen
1
H1.008
atomic number
Hydrogen
1
H1.008atomic mass
atomic number
Hydrogen
1
H1.008atomic mass
atomic numbernumber of protons
Hydrogen
1
H1.008atomic mass
atomic numbernumber of protonsnumber of electrons
Hydrogen
1
H1.008atomic mass
atomic numbernumber of protonsnumber of electrons
heavy particles
Hydrogen
1
H1.008atomic mass
atomic numbernumber of protonsnumber of electrons
heavy particles(protons + neutrons)
atomic number
atomic mass
atomic number= number of protons= number of electrons
atomic mass
atomic number= number of protons= number of electrons
atomic mass= average # of heavy particles= protons + neutrons.
Tomorrow’s daily quiz will
be on this!Element
Atomic Number Protons Electrons
A Pb 82B 8C 30D 26E 11
Atomic Mass Unit
1 AMU = 1/12 the mass of a carbon atom.
How come atomic masses aren’t whole numbers?
Atomic Mass Unit
1 AMU = 1/12 the mass of a carbon atom.Proton = 1.007276 AMU
Neutron = 1.008665 AMU
Electron = 0.000549 AMU
How come atomic masses aren’t whole numbers?
Atoms sometimes have extra neutronsExtra neutrons don’t do anything chemically…
…but they’re heavy!
How come atomic masses aren’t whole numbers?
An isotope is an atom with a different number of neutrons
The mass number is the exact number of protons + neutrons in an atom.
Five-Minute Assignment:
Page 101
Problem 14
Five-Minute Assignment: AtomicElement Number
Mass Number
Protons Electrons Neutrons
Ca 20 46
O 8 17
Fe 26 57
Zn 30 64
Hg 80 204
Calculating Atomic Mass
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them.
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them.
unknown element
X
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7XX
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7
mass 6.015 amu 7.016 amu
XX
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7
mass 6.015 amu 7.016 amu
abundance 7.50% 92.5%
XX
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7
mass 6.015 amu 7.016 amu
abundance x 7.50% x 92.5%
XX
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7
mass 6.015 amu 7.016 amu
abundance x 7.50% x 92.5%
0.451 amu 6.490 amu
XX
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7
mass 6.015 amu 7.016 amu
abundance x 7.50% x 92.5%
0.451 amu + 6.490 amu =
XX
Calculating Atomic Mass
For each isotope of an element, multiply mass × abundance and then add them. 6 7
mass 6.015 amu 7.016 amu
abundance x 7.50% x 92.5%
0.451 amu + 6.490 amu = 6.941
XX
Calculating Atomic Mass
unknown
?
X6.941
Calculating Atomic Mass
Lithium
3
Li6.941
Homework
Page 104, problems 15-21
.