Week 10 Chemistry

transcript

Week 10 ChemistryAtomic Theory, Electromagnetics, Physics Basics

Warm Up: 4 Minutes

Which model of the atom do you identify with? Explain.

Be Ready to Share Aloud

Write the Learning Target

You should be working SILENTLY

Stay in your own seat

Agenda

Warm Up: 6 Min Gallery Walk Expectations: 3 mins Gallery Walk: 20 mins Guided Practice: 11 mins Independent Practice: 12 mins Closing: 1 Min

Announcements

Assignments, syllabus, and class calendar posted on Sharpstown Website (under my page) http://www.houstonisd.org/Page/66

Go to “Faculty & Staff”

Click on Ghosh, Niloy

Assignment names have links to worksheet/activity. If you lose the assignment from class, it is your responsibility to print it out and bring it completed.

Gallery Walk Expectations

Students will remain with their group Students will not move stations until instructed to

do so by teacher Students will stay on task and remain focused for

duration of activity

Gallery Walk

You will have 4 minutes at each station Fill out the information on your guided notes

handout Do not move stations UNTIL instructed to do so

Guided Practice

Mr. Ghosh: Project a multiple question

Student will:

1. SILENTLY read the question to your self and pick an answer [21 seconds]

2. Take 39 seconds to speak with your shoulder partner to chose the correct answer and discuss why it is the correct answer. [39 seconds]

3. When Mr. Ghosh says “SWAG” all students should be SILENT

Consider the following selected postulates of Dalton’s atomic theory:

I. Each element is composed of extremely small particles called atoms.

II. Atoms are indivisible.

III. Atoms of a given element are identical.

IV. Atoms of different elements are different and have different properties.

Which of the above statements is (are) no longer considered to be true?

A. III and IV

B. II only

C. I and II

D. II and III

Consider the following selected postulates of Dalton’s atomic theory:

I. Each element is composed of extremely small particles called atoms.

II. Atoms are indivisible.

III. Atoms of a given element are identical.

IV. Atoms of different elements are different and have different properties.

Which of the above statements is (are) no longer considered to be true?

A. III and IV

B. II only

C. I and II

D. II and III

As a result of Rutherford’s gold foil experiment, it was determined that the atom:

A. was indivisible.

B. was composed of a small, dense negative center but was mostly empty space.

C. was composed of a small, dense positive center but was mostly empty space.

D. was composed of negatively charged particles spread throughout a positively charged substance

As a result of Rutherford’s gold foil experiment, it was determined that the atom:

A. was indivisible.

B. was composed of a small, dense negative center but was mostly empty space.

C. was composed of a small, dense positive center but was mostly empty space.

D. was composed of negatively charged particles spread throughout a positively charged substance

Based on his observations, the English chemist John Dalton formulated an atomic theory

In 1897, J.J. Thomson showed that negative charges could be made to move from one end of a cathode ray to another, causing the tube to glow. Because of this, Thomson is credited with the discovery of the electron. Based on this information, which part of Dalton’s atomic theory conflicted with Thomson’s new data?

Based on his observations, the English chemist John Dalton formulated an atomic theory

In 1897, J.J. Thomson showed that negative charges could be made to move from one end of a cathode ray to another, causing the tube to glow. Because of this, Thomson is credited with the discovery of the electron. Based on this information, which part of Dalton’s atomic theory conflicted with Thomson’s new data?

The planetary model of the atom was proposed by _____.

A. Bohr

B. Thomson

C. Dalton

D. Democritus

The planetary model of the atom was proposed by _____.

A. Bohr

B. Thomson

C. Dalton

D. Democritus

Independent practice

Complete the writing assignment on the scientists. You must include all of the REQUIRED information to receive FULL CREDIT

Closing

How has the atomic model changed over time?

Warm Up: 4 Minutes

How would you define light?Write a Minimum of Three Sentences

Agenda

Warm Up: 7 MinutesCornell Style notes: 18 MinutesGuided Practice: 10 Minutes Independent Practice: 15 MinutesClosing: 3 Minutes

Take out paper for notes

BLUE RED

The final model of the atom stemmed from the study of light.

By 1900, most scientists accepted the idea that light

was a wave phenomenon

According to the wave phenomenon, light consisted of ELECTROMAGNETIC RADIATIONS

λDistance between the crests

Wavelength

CHECK POINT How many wavelengths are in this wave cycle?

fNumber of wave cycles to

pass a given point per unit of given time.

Frequency

Relationship between frequency and wavelengthλ and f are opposites (inversely related)λ decreases (↓), f increases (↑)

What about energy and frequency?

Relationship between energy and frequency

Energy and frequency are directly RelatedE increases (↑), f increases (↑)

What about energy and wavelength?

Relationship between energy and wavelengthEnergy and wavelength are opposites

(inversely Related)E increases (↑), λ decreases (↓)

Check Point

Diego burns Sodium metal and watches it turn yellow at a frequency of 4.2 x 107 Hz. However, Dalvin burns an unknown metal and it emits a red light with a frequency of 2.3 x 107 Hz. Which student had the metal that emitted photons of light with a shorter wavelength?

That’s great…But what about numbers?To compare very large or very small numbers (with scientific notation, such as 105), we need to look at the exponent

Exponent Power to which a number is raised

Example: 105

5 is the exponent

The Exponent Number Line

--3 -2 -

10 1 2 3

Smaller Value Larger Value

Exponent

Check pointWhich value is larger, 3.2 x 106 or 1.8 x 109?

1.8 x 109

(Because 9 is bigger than 6)

Check pointWhich value is smaller, 6.1 x 10-5 or 8.9 x 10-7?

8.9 x 10-7

(Because -7 is smaller than -5)

Electromagnetic Spectrum

This model shows the types of electromagnetic energy (separated by their different wavelengths).

Electromagnetic Spectrum(shortest wavelength, Highest frequency)

Gamma rays X-rays Ultraviolet Visible light Infrared Microwaves Radio waves(longest wavelength, lowest frequency)

Electromagnetic Spectrum

(shortest wavelength)

Gamma rays X-rays Ultraviolet Visible light Infrared Microwaves Radio waves(longest wavelength)

Violet

Indigo

Yellow

Orange

Shortest Wavelength, Highest Frequency)

(Longest Wavelength, Lowest Frequency)

Check Point

Which portion of the electromagnetic spectrum has the lowest frequency?

a. Blue Light

b. X- Rays

c. Radio Waves

d. Infrared Waves

Guided Practice

Mr. Ghosh: Project a multiple question

Student will:

1. Silently read the question to your self and think about an an answer [19 seconds]

2. Take 41 seconds to speak with your shoulder partner to chose the correct answer and discuss the best answer choices and explain your opinion. [41 seconds]

3. When Mr. Ghosh says “SWAG” all students should be SILENT

A wave with low energy has the following properties:

a. High frequency, long wavelength

b. High frequency, short wavelength

c. Low frequency, long wavelength

d. Low frequency, short wavelength

A wave with low energy has the following properties:

a. High frequency, long wavelength

b. High frequency, short wavelength

c. Low frequency, long wavelength

d. Low frequency, short wavelength

Electromagnetic waves with high frequencies have been used for medical imaging. These waves most likely belong to which of the following parts of the electromagnetic spectrum?

a. Microwaves

b. Infrared waves

c. Radio waves

d. X-rays

Electromagnetic waves with high frequencies have been used for medical imaging. These waves most likely belong to which of the following parts of the electromagnetic spectrum?

a. Microwaves

b. Infrared waves

c. Radio waves

d. X-rays

Which of the following graphs best represents the relationship of the frequency of an electromagnetic wave to its wavelength?

As a distant star moves toward Earth, the light given off by the star has a measurably higher frequency. What happens to the wavelength and energy of the photons of light when the frequency becomes higher?

a. The wavelength becomes longer, and the energy decreases

b. The wavelength becomes shorter, and the energy decreases

c. The wavelength becomes longer, and the energy increases

d. The wavelength becomes shorter, and the energy increases

As a distant star moves toward Earth, the light given off by the star has a measurably higher frequency. What happens to the wavelength and energy of the photons of light when the frequency becomes higher?

a. The wavelength becomes longer, and the energy decreases

b. The wavelength becomes shorter, and the energy decreases

c. The wavelength becomes longer, and the energy increases

d. The wavelength becomes shorter, and the energy increases

Independent Practice

Practice Makes 85%

Closing

Which direction is frequency increasing? Wavelength?

Warm Up: 5 Minutes

You took your second assessment on Thursday. Answer the following questions about the assessment in COMPLETE SENTENCES:

How do you think you performed on Assessment 2? What did you do to prepare for Assessment 2? What could you have done to better prepare for

Assessment 2?

Just Something to Think About?

“Obstacles are those frightful things you see when you take

your eyes off your goal.”

- Henry Ford

Agenda

Warm Up [7 minutes] Review: Purpose of tracking [5 minutes] Answer Key [ 8 minutes] Modeling Tracking [10 minutes] You Track [ 10 minutes] Rationalize Questions /Corrections[10

minutes]

Closing: [3 Minutes]

Answer KeyAs Mr. Ghosh goes through the answers, highlight the ones you got wrong1. B

TrackingMethod to

measure your performance on specific skills or objectives.

Purpose of Tracking

For students to know which skills you have mastered and which skills need some work

When Will You Track??You will track

after every Unit Assessment.

What does Tracking Look Like?

Objectives

Questions on the Exam

Your Points

Total Points

Percent Mastery

Bar Graph

Mastery85% or

Chem.4A Physical

and Chemical

Objectives

Your Points

Total Points

Percent Mastery

Bar Graph

Mastery85% or

Chem.4A Physical

and Chemical

Objectives

Your Points

Total Points

Percent Mastery

Bar Graph

Mastery85% or

Chem.4A Physical

and Chemical

1-5 ???

[3 if you got 3

out of 5 correct]

Objectives

Your Points

Total Points

Percent Mastery

Bar Graph

Mastery85% or

Chem.4A Physical

and Chemical

1-5 ???

[3 if you got 3

out of 5 correct]

Objectives

Your Points

Total Points

Percent Mastery

Bar Graph

Mastery85% or

Chem.4A Physical

and Chemical

1-5 ???

[3 if you got 3

out of 5 correct]

5 Your points x100 Total points

Percent MasteryCathy received 1 point out

possible points. What is

her percent mastery?

Your points x100 Total points

Objectives

Your Points

Total Points

Percent Mastery

Bar Graph

Mastery85% or

Chem.4A Physical

and Chemical

1-5 ???

[3 if you got 3

out of 5 correct]

5 Your points x100 Total points

Shade in your % mastery

You Do It

Use your assessment to determine what you’re good at and what you need help with ….

On a piece of paper, write Mr. Ghosh a letter addressing all the following questions in complete sentences for full credit. [5 Minutes]

1. What will you do to ensure that you master the objectives that you didn’t perform well on?

2. Does your grade reflect how hard you worked?

3. Are you proud of your grade?

4. Is your grade reflective of your best work?

What Next??

Corrections

For each number you got incorrect:

1. Write the number of the question.

2. Write the letter you chose.

3. Re-evaluate the question and chose a different answer and explain why you chose a different answer.

Closing

Reflect on the effort you have put into this class thus far, what are your next steps that need to be implemented so that we can reach our big goal?

Warm Up: 4 Minutes

As a distant star moves away from earth, the light given off by the star has a measurably lower frequency. What happens to the wavelength and energy of the photons of light when the frequency becomes lower?

A. The wavelength becomes longer, and the energy decreases

B. The wavelength becomes shorter, and the energy decreases

C. The wavelength becomes longer, and the energy increases

D. The wavelength becomes shorter, and the energy increases.

Agenda

Warm Up: 7 Minutes Examples: 15 MinutesGuided Practice: 13 Minutes Independent Practice: 15 MinutesClosing: 3 Minutes

BLUE RED

Concept Symbol Unit

Wavelength

Concept Symbol Unit

Wavelength

Concept Symbol Unit

Wavelength

λ Meters, m

Concept Symbol Unit

Wavelength

λ Meters, m

Frequency

Concept Symbol Unit

Wavelength

λ Meters, m

Frequency f

Concept Symbol Unit

Wavelength

λ Meters, m

Frequency f Hz or 1/s

Speed of Light (C)

3.00 x 108 m/s

Speed of Light Formula

Important !

DO NOT FORGET YOUR UNITS!!!If you are finding frequency, your units should be in HzIf you are finding wavelength, your units should be in meters (m)

How do we use this formula?

If you have frequency, and need to find wavelength?

How do we use this formula?

If you have wavelength, and need to find frequency?

You Will Need a Calculator…

Example 1

Calculate the wavelength of the yellow light emitted by a sodium lamp if the frequency of the radio is 5.10 x 1014

G U E S S

How to put this in the calculator?

C = 3.00 x 108

On calculator: 3.00

f = 5.10 x 1014

On calculator: 5.10[2nd]X-1

On the Calculator, pressing “[2nd] X-1” is the same as “x 10n” in the problem

𝜆=𝐶𝑓

= 3.00×108

5.10×1014

Answer:

0.000000588 m

Example 2

The yellow light given off by a sodium vapor lamp used for public lighting has a wavelength of 5.89x 10-7 m. What is the frequency of this radiation?

G U E S S

C = 3.00 x 108

On calculator: 3.00

λ = 5.89 x 10-7

On the Calculator, pressing “[2nd] X-1” is the same as “x 10n” in the problem

𝑓 =𝐶𝜆

= 3.00×108

5.89×10−7

Answer:

5.09 x 1014 Hz

We DO (3)

The FM radio station KJAZ broadcasts at 2.95 x 105 Hz. What is the wavelength of the Radio Waves broadcast by this station?

G U E S S

𝜆=𝐶𝑓

=3.00×108

2.95×105

Answer:

1016.95 m

We do (4)

The wavelength of an argon laser’s output is 4.61 x 10-9 m. Calculate the frequency of this wavelength of electromagnetic radiation.

G U E S S

Answer:

6.51 x 1016 Hz

Keep Practicing

INDEPENDENTLY

Closing

Which equation establishes the relationship between wavelength and

frequency?

Warm Up: 4 Minutes

A certain electromagnetic wave has a frequency of 24 x 109 Hz. What is its wavelength?

A. 80 meters

B. 0.0125 meters

C. 8 meters

D. 0.125 meters

Agenda

Warm Up: 6 Minutes Examples: 12 MinutesGuided Practice: 9 Minutes Independent Practice: 10 MinutesClosing: 3 Minutes

Let’s See this in Real Life!!

http://www.youtube.com/watch?v=RQTAJkC4Xc4&noredirect=1

BLUE RED

Energy (E)

The ability to do work

Units are Joules (J)

Planck’s constant (h)

6.63 x 10-34 J ·sec

Energy Formulas

Energy

𝑬=𝒉𝒇 𝑬=𝒉𝒄𝝀

Check Point

What is c?

Speed of Light

What is its value?

3.00 x 108 m/s

Check Point

What is h?

Planck’s constant

What is its value?

6.63 x 10-34 J·sec

Check Point

What is f?

Frequency

What are its units?

Hz or 1/s

Check Point

What is λ?

Wavelength

What are its units?

Meters (m)

Important !

DO NOT FORGET YOUR UNITS!!!

Energy is in Joules!

You Will Need a Calculator…

Example 1

The human eye can see light with a frequency about as high as 7.9 x 1014 Hz, which appears violet. Calculate the energy that one photon of violet light carries.

G U E S S

h = 6.63 x 10-34

On calculator: 6.63

f = 7.9 x 1014

On the Calculator, pressing “[2nd] X-1” is the same as “x 10” in the problem

𝐸=hf=( 6.63×10− 34 )∗ ( 7.9×1014 )

Answer:

5.24 x 10-19 J

Example 2

Calculate the smallest increment of energy that is the quantum of energy, which an object can absorb from a red light whose wavelength is 772 m.

G U E S S

λ = 772

On calculator: 772

On the Calculator, pressing “[2nd] X-1” is the same as “x 10” in the problem

𝐸=h𝑐𝜆

=( 6.63×10− 34 )∗ (3.00×108 )

772h = 6.63 x 10-34

On calculator: 6.63

XC = 3.00 x 108

On calculator: 3.00

Answer:

2.58 x 10-28 J

We DO (3)

What is the energy of a photon of light that has a frequency of 9.35 x 1021 Hz?

G U E S S

𝐸=hf=( 6.63×10− 34 )∗ ( 9.35×1021)

Answer:

6.20 x 10-12 J

We do (4)

An argon laser emits light at a wavelength of 4.89 x 10-7 m. What is the energy of this light?

G U E S S

Answer:

4.07 x 10-19 J

Keep Practicing

INDEPENDENTLY

Closing

Which equation establishes the relationship between wavelength and

Energy? Between Frequency and Energy?

Week 10 Chemistry

Documents