Atoms and Molecules Monday, August 29, 2011

1. Open your journals to PAGE 27. Write “Black Box Inquiry” and 8/29/11 on the top line of the page.

2. Write the following on the next line of the page “Key Question – How do scientists know what molecules and atoms look like?”

3. Examine the sealed box. What do you think is inside? NO, you may NOT OPEN the box.

4. Discuss your ideas with your team.

5. Answer the following questions on page 27

1. What things do you think are in the box?

2. What influenced your thinking?

3. How did your group work out any differences of opinions of what was in your box?

4. How does this activity help you understand how scientists know what atoms and molecules look like?

Science Standard

S8P1. Students will examine the

scientific view of the nature of matter.

a. Distinguish between atoms

and molecules.

Today’s

Essential Question

How do scientists know what atoms look like?

Today’s Learning Goals

1. Identify and describe the three

subatomic particles, their charges, and

their location.

2. Construct model of four atoms.

3. Determine the total charge of an elemental atom is neutral.

Turn to page 28 of your

journal. At the top of the

page, write “Atom Notes”

and 8/29/11.

What is an atom?

An atom is the smallest particle into which

an element can be divided and still be the same substance.

What is an element?

An element is a pure substance that cannot be

separated into simpler substances by physical or chemical means.

Recapping…

An element is pure substance in which all

particles are the same. The particles that make

up an element are atoms.

For example, if you had a bowl of carbon,

every atom would be the same.

Atoms are:

a) too small to be seen by the human eye

b) contain a lot of empty space

c) have a nucleus made up of protons and neutrons

d) have electrons moving around the nucleus in a

“cloud”

All Matter is:

a) has mass

b) takes up space (volume)

c) is made up a smaller pieces called atoms

• ELECTRONS

• Smallest • Negative

charge

• PROTONS

• Second largest • Positive

charge

• NEUTRONS

• Largest • No charge

(neutral)

•Subatomic Particles Every atom is made up of…

An elemental atom has an equal number

of electrons (negative) and protons

(positive). The total charge of the atom is

zero or neutral.

For example, if an atom has 3 protons (+ + +) and

three electrons (- - -), the resulting charge would

be zero! Each positive charge (+) and each

negative charge (-) cancel each other out.

What holds the subatomic

particles together?

The electrons moving around the nucleus

in an atom are ATTRACTED to the protons.

However the protons in the nucleus

should REPEL or push each other away.

So... what holds the nucleus together?

Small particles called mesons hold the

protons and neutrons together in the

nucleus.

Laws of Electrical Charges

Like charges repel and unlike charges

attract

WE can use models to…

1) picture what we can not see 2) make predictions based on the model

If an atom is too small to be seen, how

can we study atoms?

In the Bohr model of the atom, electrons

are visualized as orbiting the nucleus like

planets orbiting Sun. There is a limit to the

number of electrons in any orbit because

electrons PUSH EACH OTHER AWAY (repel

each other).

The first electron level (orbit) allows __2__ electrons

before electrons start filling the next level.

The second electron level (orbit) allows _8___

electrons before electrons start filling the next level.

The third electron level (orbit) allows __8__

electrons before electrons start filling the next level.

The fourth electron level (orbit) allows _18__

electrons, and so forth...

Let’s construct a model of an atom with…

2 protons

2 neutrons

2 electrons

Nucleus

1st electron level

P

P

N

N

e-

e-

Let’s construct a model of an atom with…

4 protons

4 neutrons

4 electrons

P

P

N

N

e-

e-

P

P

N N e-

e-

Using the models at your table, construct

models for these atoms below:

1) 1 electron, 1 proton

2) 6 electrons, 6 protons, 6 neutrons

3) 8 electrons, 8 protons, 8 neutrons

4) 11 electrons, 11 protons, 12 neutrons

Raise your hands as a team when all

Four models are correctly built!

1. With a card in hand, each student mixes around

the room. Each finds a partner and quizzes him or

her by asking a question relating to their card.

2. Partner answers. Praise or coaching is given.

3. Switch roles. The other partner asks, then praises or

coaches.

4. Partners trade cards.

5. Partners split up and repeat steps 1 through 4.

6. Teacher calls “Freeze!”.

7. Students freeze, hide their cards, and think of their

match.

8. Students move to the center of the room,

find their match, and quickly move away

from the center of the room with their new partenr.