Chap 18 Bell -Ringers

Chap 4 Bell -Ringers

The

Structure

of the Atom

The Atom has a

Structure

Chapter 1The 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 2Matter and Atoms


- 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.




Physical and Chemical Change






How can we explain the

properties and behaviors

observed so far?



Chapter 3Temperature, 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

Democritus

Atomism

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

Democritus

Atomism

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



atomic theory.

Today1808

Democritus

Atomism

460 – 370 BC






other element.

3. Chemical reactions rearrange atoms but

do not create, destroy, or convert atoms

from one element to another.




atomic theory.

Today1808

Democritus

Atomism

460 – 370 BC


4. Compounds are made from combining

atoms in simple whole number ratios.





other element.

3. Chemical reactions rearrange atoms but

do not create, destroy, or convert atoms

from one element to another.




atomic theory.

Another kind of light?

Today1808 1870

Democritus

Atomism

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.


Today1808 1870 1897

Democritus

Atomism

460 – 370 BC

Dalton

“Modern”

atomic theory

Crookes

Cathode rays

Cathode rays

must be negative.

J.J. Thomson

discovers the

electron

Today1808 1870 1897 1910

Democritus

Atomism

460 – 370 BC

Dalton

“Modern”

atomic theory

Crookes

Cathode raysThomson

Discovery

of the electronErnest Rutherford

discovers the

nucleus


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

nitrogen8 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-13 Carbon-14

# protons

# neutrons

Mass

number 12 13 14


# protons

# neutrons

Mass

number 12 13 14


# protons 6 6 6

# neutrons

Mass

number 12 13 14


# 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

Crookes

Cathode raysThomson

Discovery

of the electron

Rutherford

Discovery

of the nucleus

Democritus

Atomism

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% 0% 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

0% 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

0% 0% 0%0%0%

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% 0% 0%0%0%

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% 0% 0%0%0%

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%0%

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% 0% 0%0%0%

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

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.

..

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

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.

..

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

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic

force

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% 0% 0%0%0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic

force

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% 0%0%0%0%

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic

force

The force that holds the

positively charged nucleus

together is called

Pro

ton

Neu

tron

Ele

ctro

n

Nucl

eus

Energ

y le

vels

Mass

num

ber

Ele

ctro

magne

tic fo

rce

Strong n

uclea

r fo

rce

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

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic

force

8. Strong nuclear force

The force that holds the atom

together is called

1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic

force

8. Strong nuclear force

The total number of protons and

neutrons in the nucleus of an

atom1. Proton

2. Neutron

3. Electron

4. Nucleus

5. Energy levels

6. Mass number

7. Electromagnetic

force

C-12

How many

protons?

How many

electrons?

How many

neutrons?

Draw a atomic

model for this

element?

6

6

6

6 p+

6n0

2 4

14

6

How many

protons?

How many

electrons?

How many

neutrons?

Draw a atomic

model for this

element?

6

6

8

6 p+

8n0

2 4

7

3

How many

protons?

How many

electrons?

How many

neutrons?

Draw a atomic

model for this

element? 3 p+

4n0

3

3

4

2 1

14How many

protons?

How many

electrons?

How many

neutrons?

Draw a atomic

model for this

element? 7 p+

7n0

7

7

7

2 5

Na-23How many

protons?

How many

electrons?

How many

neutrons?

Draw a atomic

model for this

element?

11

11

12

11 p+

12n0

2 8 1

238How many

protons? 92

How many

neutrons?

238-92 = 146

Be-9

atomic number?

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%0%

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%0%0%

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9

number of neutrons?

1 2 3 4 5 6 11

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

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9

number of energy levels?

1 2 3 4 5 6 11

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

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

14Si

valence electrons?

1 2 3 4 5 6 11

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

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

7N

valence electrons?

1 2 3 4 5 6 11

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

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

Be-9

number of electrons in the first

energy level?

1 2 3 4 5 6 11

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

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 11

17Cl

number of electrons in the first

energy level?

1 2 3 4 5 6 11

0% 0% 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

1. Who discovered the electron?

2. Electrons in the outer energy are

called?

3. The columns in the periodic table

are called

• NEED YOUR PERIODIC TABLE

FOR THIS ONE

Find SULFUR (atomic # 16)

• How many valence electrons

does it have?

• Which orbital is being filled?

1. Element or compound??

Hydrochloric acid HCl

2. What element is most closely

related to Bromine?

3. What does the group # tell us?

• 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”?

A

B

C

Which orbital is represented by :

A? B? C?s d p

Which 2 orbitals are we most concerned with

because of valence electrons? s and p

A

B

C

Which are the metals?

Nonmetals?

A

B

Documents

Chap 18 Bell -Ringers