chap 4 bell -ringers. the structure of the atom the atom has a structure

Chap 4 Bell -Ringers

The Structure

of the Atom

The Atom has a Structure

Chapter 1 The Science of Chemistry

What we’ve seen so far…- Chemistry is about discovering and understanding natural laws using the scientific method

- Energy cannot be created nor destroyed

- Matter can be mixtures or substances. The smallest unit of a pure substance is an element.

- Each element is a type of atom, and they can be arranged in a periodic table.

- Atoms come together to form compounds. Atoms with an electric charge are known as ions.


Chapter 2 Matter and Atoms

What we’ve seen so far…

- Temperature is a measure of kinetic energy.

- Heat is thermal energy.

- Heat gain and heat loss can cause phase changes, as molecules are rearranged.



Chapter 3 Temperature, Energy, and Heat


- In a physical change molecules are rearranged. In a chemical change atoms are rearranged to make new substances.

- Chemical reactions can be endothermic or exothermic.

- Many reactions occur in aqueous solution, and some elements are more reactive than others.



Temperature, Energy, and Heat

Physical and Chemical Change




Temperature, Energy, and Heat


How can we explain the properties and behaviors observed so far?



Chapter 3 Temperature, Energy, and Heat


How can we explain the properties and behaviors observed so far?

Answers can be found inside

the atom

92 different types of atoms!

Each of the elements is a unique type of atom.

Atoms are made from smaller particles!

electrons

protons

neutrons

How did scientists come up with this?

Atoms are made from smaller particles!

electrons

protons

neutrons

It started a long time ago…Today460 – 370 BC

Democritus

Beginning of Atomism

You cannot divide something in half forever.

The smallest piece of matter is called an atom.

How do you find out about something you can’t see?

Think of the conservation of mass labs, distilled wood, even flame test lab

Think of experimentation of the Copper, HCl and Zinc lab

Think of the Rutherford marble tossing lab

Bellringer

When scientists wanted to find out what an atom was, they were not able to look directly at what the atom was made of. They had to make inferences from the results of many different experiments. It was like trying to describe a picture, such as the one on the next slide, with only small portions visible.

Bellringer, continued

1. Write four sentences describing what you can see of the above picture.

2. What information or parts of the picture would make your descriptions more accurate without revealing the entire picture?

Scientists contributing

DALTON

BOHR

CHADWICK THOMSON

de BROGLIE

RUTHERFORD

Today1808

DemocritusAtomism

460 – 370 BC

Dalton’s Postulates

1. All elements are made of tiny indivisible particles called atoms.

Over 2,000 years later John Dalton comes up with the first “modern” atomic theory.

Today1808

DemocritusAtomism

460 – 370 BC



2. All atoms of the same element are the same, but different from atoms of

every other element.Over 2,000 years later John Dalton comes up with the first “modern” atomic theory.

Today1808

DemocritusAtomism

460 – 370 BC




every other element.

3. Chemical reactions rearrange atoms but do not create, destroy, or convert atoms from one element to another.


Today1808

DemocritusAtomism

460 – 370 BC


4. Compounds are made from combining atoms in simple whole number ratios.



every other element.

3. Chemical reactions rearrange atoms but do not create, destroy, or convert atoms from one element to another.


Another kind of light?Today1808 1870

DemocritusAtomism

460 – 370 BC

Dalton“Modern”

atomic theory

William Crookes invents a tube in which virtually all the gas has been removed.

Under high voltage, a ray was emitted from the cathode end of the tube.

It started a long time ago…Today1808 1870 1897

DemocritusAtomism

460 – 370 BC

Dalton“Modern”

atomic theory

CrookesCathode rays

Cathode rays must be negative.

J.J. Thomson discovers the electron

Today1808 1870 1897 1910

DemocritusAtomism

460 – 370 BC

Dalton“Modern”

atomic theory

CrookesCathode rays

ThomsonDiscovery

of the electronErnest Rutherford discovers the nucleus

It started a long time ago…

The size of the atom comes

mostly from the space occupied by

the electrons

The mass of the atom comes mostly from the nucleus

Size and mass

Charges in the atom

electronsprotons

neutrons

A complete atom has a charge of zero

Charges in the atom

Charges in the atom

electronsprotons

neutrons

What happens when you change the number of protons?

You obtain a different element!

6 protons in carbon

7 protons in nitrogen

8 protons in oxygen

The number of protons is also called

the atomic number for that element.

The electron cloud

Except for mass, virtually every property of atoms is

determined by electrons, including size and chemical bonding

Electrons are very light and fast.

They are not organized along orbits around the nucleus.

electronsprotons

neutrons

What happens when you change the number of neutrons?

Atomic number

Neutrons act as “glue.” They hold protons together in the nucleus.

mass number: total number of protons and neutrons in a nucleus.

Mass number = 6 p + 6 n = 1212C

“carbon-12”

Mass number

Name

# protons

# neutrons

Mass number

Name Carbon-12 Carbon-13Carbon-14

# protons

# neutrons

Mass number 12 13 14


# protons

# neutrons



# protons 6 6 6

# neutrons



# protons 6 6 6

# neutrons 6 7 8

isotopes: atoms or elements that have the same number of protons in the nucleus but different number of neutrons.

Two lithium isotopes in nature

Atomic mass

How can lithium have 0.941 neutrons?

Number of neutrons for each of 100 lithium atoms randomly sampled from nature

It’s an AVERAGE mass!

Isotope periodic table (first 4 rows)

There must be a force that keeps the

nucleus together

Forces in the atom

In the nucleus Electrons

Electrons repel each other, but don’t “fall into” the nucleus because they are

in constant motion.

Electrons form bonds between atoms.

Forces in the atom

The strong nuclear force attracts protons to protons, neutrons to

neutrons, and protons to protons

Today1808 1870 1897 1910460 – 370 BC

Dalton“Modern”

atomic theory

CrookesCathode rays

ThomsonDiscovery

of the electron

RutherfordDiscovery of the nucleus

DemocritusAtomism

electronsprotons

neutrons

The size of the atom comes mostly from the electrons

The mass of the atom comes mostly from the nucleus

Who coined the term atom in 4 BC?

Dal

ton

Dem

ocritu

s

Ruth

erfo

rd

Bohr

Thom

son

0%

100%

0%0%0%

1. Dalton

2. Democritus

3. Rutherford

4. Bohr

5. Thomson

Who stated that elements are made of indivisible spheres called atoms?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

100%

0% 0%0%0%

1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who discovered the atom was divisible and had subatomic parts?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

5%0%

71%

10%14%

1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who discovered the electron?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

0%

17%

48%

4%

30%

1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who discovered that atoms are mostly empty space?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

0% 4% 0%0%

96%1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who discovered the nucleus?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

0% 0% 0%0%

100%1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who discovered the proton in the nucleus?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

0%

9%

0%5%

86%1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who stated that electrons are located in fixed energy levels?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

0%

62%

0%

38%

0%

1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Who discovered the neutron?

Dal

ton

Chad

wic

k

Ruth

erfo

rd

Bohr

Thom

son

0%

96%

0%4%0%

1. Dalton

2. Chadwick

3. Rutherford

4. Bohr

5. Thomson

Center of a atom, contains most of the atom’s mass

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Ener

gy le

vels

Mas

s num

ber

Ele

ctro

mag

neti.

..

0%5%

0% 0%5%

0%

91%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic force

Positively charged particle that exists in the nucleus

of an atom.

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Ener

gy le

vels

Mas

s num

ber

Eel

ctro

mag

neti.

..

96%

0% 0% 0%0%0%4%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Eelctromagnetic force

Particle with no charge that exists in the nucleus of an atom

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Ener

gy le

vels

Mas

s num

ber

Ele

ctro

mag

neti.

..

4%

96%

0% 0%0%0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number


The least massive of the three subatomic particles which also carries an negative net charge.

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Ener

gy le

vels

Mas

s num

ber

Ele

ctro

mag

neti.

..

0% 0%

100%

0%0%0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number


Describes how electrons are arranged around an atom

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Ener

gy le

vels

Mas

s num

ber

Ele

ctro

mag

neti.

..

0% 0% 0%4%

0%

96%

0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number


The force that holds the positively charged nucleus

together is called

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Energ

y lev

els

Mass

num

ber

Ele

ctro

magne

tic fo

rce

Stro

ng nucl

ear f

orce

0% 0% 0%

82%

18%

0%0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number


8. Strong nuclear force

The force that holds the atom together is called

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Energ

y lev

els

Mass

num

ber

Ele

ctro

magne

tic fo

rce

Stro

ng nucl

ear f

orce

0% 0% 0%

12%

88%

0%0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number


8. Strong nuclear force

The total number of protons and neutrons in the nucleus of an

atom

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Ener

gy le

vels

Mas

s num

ber

Ele

ctro

mag

neti.

..

0% 0% 0% 0%

100%

0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number


C-12

How many protons?

How many electrons?

How many neutrons?

Draw a atomic model for this element?

C14

6

How many protons?

How many electrons?

How many neutrons?


Li 7

3

How many protons?

How many electrons?

How many neutrons?


N 14

How many protons?

How many electrons?

How many neutrons?


Na-23 How many protons?

How many electrons?

How many neutrons?


U238

How many protons?

How many neutrons?

Be-9atomic number?

1 2 3 4 5 6 11

0% 0% 0% 0%0%4%

96%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9 number of protons?

1 2 3 4 5 6 11

0% 0% 0% 0%0%0%

100%1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9 number of electrons?

1 2 3 4 5 6 11

0% 0% 0% 0%0%4%

96%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9number of neutrons?

1 2 3 4 5 6 11

0% 0% 0% 0%0%

100%

0%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9number of energy levels?

1 2 3 4 5 6 11

0%

96%

4%0%0%0%0%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

14Sivalence electrons?

1 2 3 4 5 6 11

0% 0%

13%

0%0%0%

88%1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

7Nvalence electrons?

1 2 3 4 5 6 11

0%4%

0% 0%0%

96%

0%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9number of electrons in the first

energy level?

1 2 3 4 5 6 11

0%

100%

0% 0%0%0%0%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

17Clnumber of electrons in the first

energy level?

1 2 3 4 5 6 11

0%

100%

0% 0%0%0%0%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Complete the energy levels …

• # of Protons?• # electrons?

• # e’ in 1st orbital?• # e; in 2nd orbital?• # of valence e’ ?

NITROGEN

7

2

5

5

7

1. Who discovered the electron?

2. Electrons in the outer energy are called?

3. The columns in the periodic table are called

JJ Thomson

Valence electrons

Groups

• NEED YOUR PERIODIC TABLE

FOR THIS ONE

Find SULFUR (atomic # 16)• How many valence electrons

does it have?• Which orbital is being filled?

63rd

1. Element or compound?? Hydrochloric acid HCl

2. What element is most closely related to Bromine?

3. What does the group # tell us?

Compound

Fluorine / Chlorine

The # of valence electrons

• 1. Who did the gold-foil experiment?

• 2. Who stated that elements are made of atoms?

• 3. What does the period # tell us?

• 4. Who created the term “atomos”?

Rutherford

Dalton

# of the energy level being filled

Democritus

A

B

C

Which are the metals?

Nonmetals?A

B

chap 4 bell -ringers. the structure of the atom the atom has a structure

Documents

atom slide

atoms chapter

lab slide

structure slide

science of chemistry

atoms temperature

chemical change atoms

broglie rutherford slide