daily quiz. 1.where is the proton located? a.in the nucleus b.in a cloud around the nucleus c.both...

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

.