Do Now: (3 min)

Lauren was cooking pasta in the pot. When it’s done cooking, she needs to separate the pasta from the water. What separation technique does she use and why?

In order to get points for your Do Now, bring it up to the front to get checked off

Do Now Discussion

Lauren was cooking pasta in the pot. When it’s done cooking, she needs to separate the pasta from the water. What separation technique does she use and why?

Filtration! She’s removing a solid from a liquid!

The Atom

10/20/09Video notes, Stations

The AtomThe smallest particle of an element

that retains all the properties of that element – the building block of everything!

Today we are learning about:The history of the atomThe experiments used to make

modelsThe current model and structure of

the atom

Today’s Agenda

1. Video on the Atom2. Stations: Parts of the Atom3. Discussion and summary4. Reflection

Video: History of the AtomVery quick (5 minutes)Pay attention because the

information will be useful to you in the next activity

If we find it hard to pay attention – we can take cornell notes instead

Stations: Parts of the Atom In your notes, divide a sheet of paper into four

sections (one section for each station0 Work in groups of 2 of your choice 4 minutes at each station to complete the

following tasks:1. READ ALL of the information at the

station2. Answer the questions at the bottom of

each station (on the back of our notes sheet)

3. Fill in the blanks on our notes sheet that we missed during the video

NOTE: If the work does not get done, we will lose the opportunity to choose our partners in the future.

If you finish early – keep working at the same station (make your answer better!)

What have we learned? (short cornell notes)Atom: The smallest particle of an element

that retains all the properties of that element

Cathode Ray Experiment: discovery of the electron

Gold Foil Experiment:◦ Particles pass through foil atoms are mostly

empty space◦ Particles bounce off atoms have a solid

center called the nucleus

Today’s Model:◦ Proton – in the nucleus, positive charge◦ Neutron – in the nucleus, neutral (no charge)◦ Electron –outside of the nucleus, negative

charge.

Reflection:

At the bottom of your notes, write about what you learned today:

What are TWO things you learned today you didn’t know before?

What topics do you find confusing?

What questions do you have?

The AtomThe smallest particle of an element

that retains all the properties of that element

Atoms are too small for us to see, but we know they are made of three types of particles: the proton, the neutron, and the electron.

Scientists use experiments to get clues to construct models

Atomic Theory (the first model)John DaltonMain points

◦Atoms are small parts that make up atoms

◦Atoms of a specific element are different from those of another element

◦Atoms cannot be created nor destroyed divided into smaller parts

Experiment 1: The cathode rayJ. J. ThompsonNoticed when you placed a

magnet near a cathode ray, it BENDS

Means the particles in the ray must be negatively charged!

Plum Pudding ModelJ. J. ThompsonDiscovered the electron

(negatively charged particle)Because matter is neutral, it

must have both positively and negatively charged particles

Proposed a model where electrons are like chocolate chips

Gold Foil ExperimentErnest RutherfordShot positively charged particles at thin

sheet of gold foilMost particles passed through ATOMS ARE

MOSTLY EMPTYSPACESome particles bounced off atoms have a

positively charged mass called the NUCLEUS

Today’s Model: Parts of the AtomThe Proton:

◦ Positively charged (1+)◦ Located in the nucleus

The Neutron:◦ No charge (0)◦ Located in the nucleus

The Electron ◦ Negatively charged (1-)◦ Move around the nucleus in the electron

cloud

ReflectionWrite your name, date and period on a separate sheet

of paper and answer the following questions:

1. Define an atom in your own words2. What subatomic particle did JJ Thompson discover

and what does it look like in the Plum-Pudding Model?

3. In the gold foil experiment, most particles passed through the foil. What does that say about atoms?

4. In the gold foil experiment, some particles bounced off. What does that say about atoms?

5. A proton is ____________ charged and is located ______________.

6. A neutron is __________ charged and is located _______________.

7. An electron is _________ charged and is located __________________.