Atomic Theory Lesson - Weeblycsouders.weebly.com/uploads/6/3/7/8/6378620/atomic_theory_lesson… · Atomic Theory C. Souders – Battlefield Standard of Learning SOL CH.2 a, b, i:

Atomic Theory

C. Souders – Battlefield

Standard of Learning

SOL CH.2 a, b, i: The student will demonstrate an understanding of the development of the current atomic model.

Essential Question(s)

How does experimentation support constant change in our model of the atom? What are the three fundamental particles of the atom? How are the fundamental particles of matter used to determine atomic mass and number?

Unit: The Periodic Table Lesson: Atomic Theory Time Frame: 180 minutes (2 blocks)

PWCS Standards Based Planning Process Standards: What will students know and be able to do?

Essential Understandings -

The periodic table is arranged in order of increasing atomic number.

There are three fundamental particles of the atom (protons, neutrons, and electrons) which are used to determine atomic mass, atomic number, and isotopic characteristics.

Major insights regarding the development of the current atomic model and principal contributing scientists include:

o particles Democritus o first “modern” atomic theory of matter John Dalton o discovery of the electron J. J. Thompson o discovery of the nucleus Ernest Rutherford o discovery of the charge on the electron Robert Milliken o planetary model of the atom Neils Bohr o quantum nature of energy Max Planck o uncertainty principle Werner Heisenberg o wave theory Louis de Broglie

Essential Skills –

Given a set of real or “synthetic” symbols with appropriate numerical notations, arrange them as they would appear in the periodic table.

Using a periodic chart, determine the atomic number, atomic mass, number of protons, number of neutrons, and number of electrons of any neutral atom. Define both qualitatively and quantitatively the essential sub atomic particles that make up an atom.

Relate where each of the essential sub atomic particles “resides” within an atom.

Match the insight / discovery with the appropriate scientist.

Explain the emergence of modern theories based on historical development; for example, students should be able to explain the origin of the atomic theory

beginning with the Greek atomists and continuing through the most modern Quantum models.

Assessment: How will the student and I know when he/she is successful?

Before Lesson (Pre-Assessment) – Most students have been exposed to the concepts of atoms, subatomic particles and the periodic table in middle school. Some students may have some experience with the terms ‘ion’ and ‘isotope’ however this will be knew to many students, along with the atomic mass. The warm-up should give the teacher a feel of what the students know and how much needs to be reviewed. The warm-up will be given and the teacher will call on students to share their responses verbally or by writing on the board.

During Lesson (Formative) – This lesson includes a theory portion as well as a mathematical portion to this lesson, it can be difficult for students to switch from one concept to another. Attached is a PowerPoint as well as a Venn diagram graphic organizer that can be used to help differentiate between the subatomic particles. There are also two activities that will allow for checking how much the students understand and what needs to be elaborated on. There is also a Timeline Activity that could be used as an assessment after the first part of the lesson or can be used as a group activity to make sure there is a strong understanding of the scientists and what they were responsible for. Teacher should consistently ask questions prompted by discussion and images in the PowerPoint. Students tend to struggle with this because students cannot see atoms or subatomic particles with the naked eye. Students have a hard time conceptualizing the atom and believing that it is there.

After Lesson (Summative) – There is a quiz included for an end of lesson assessment. This information would also need to be included in a cumulative unit test. This should be evaluated before moving on to the next lesson as students should be easily able to identify subatomic particles in any given element. If more practice is needed on understanding what scientists are responsible for each development of the atomic model the Timeline Activity could also be done at the end of the lesson or as a warm-up for the next lesson.

Task Analysis: What knowledge, skills and level of understanding do students need to be successful with this lesson?

Pre-Assessment Data: There should be some information that can be pulled from previous knowledge; the concept of atom, protons, neutrons, electrons,

etc. However, for some students this will be a completely new topic because this lesson comes at the beginning of the school year and where not much instruction has been completed with students.

Important Vocabulary (Literacy) – Skill Development and Differentiation– Some of the activities can be altered easily to differentiate for students based on their needs.

o The Atoms, Ions, Isotopes Activity is great for kinesthetic learners. It is a hands on activity that allows students to visualize the subatomic particles which they cannot normally see. This activity can be edited simply by varying the number of “atoms” the students have to identify. Some students may need more time on one item.

o There is a Venn diagram included to help students identify the similarities and differences between subatomic particles. Some students may not need this tool but it can be very helpful for students who are struggling.

o The Atomic Mass of Candium lab should help students to understand the idea of isotopes. For students who are struggling with this concept, you could reduce the number of different candies to two and for those who need more of a challenge you could increase the number to give more isotopes.

o The Timeline Activity can be easily edited. The teacher can scaffold the assignment based on students abilities. It can be simplified by putting the scientists in order or just matching their findings with the correct scientist. It can also be made more difficult by requiring students to utilize the “wild cards” to insert additional information.

Electron Proton Atomic mass unit (amu) Daltons atomic theory

Period Group Periodic table Nucleus

Atom Cathode ray Atomic mass Mass number

Neutron Isotopes Atomic number

PWCS Standards Based Planning Process (continued)

Instruction Using Inquiry Model: What learning experiences will facilitate student success?

Framing the Learning: 1. Engage – Teacher will start with the Warm-Up activity included. Once students have answered each question on their own the teacher will ask

students to share their responses verbally or by writing on the board. This should help to get students focused on the concept at hand as well as give the teacher an idea of their previous knowledge.

Learning Experiences: 2. Explore – There are two exploration activities included.

a. Atoms, Ions and Isotopes Activity – this activity is great for reinforcing the concept of ions and isotopes. It also allows students to ‘touch’ the subatomic particles which helps them to visualize their use. It is important to watch students and make sure that they are actually counting the particles and are not copying off someone else who has already finished this station. The teacher should make sure to watch how the students write the notation on the front side of the page. Students tend to assume they know what they are doing and incorrectly write it, even with examples given to them.

b. Atomic Mass of Candium Lab – Students love this activity because it really shows the concept of calculating the average atomic mass. Teachers can edit this lab to incorporate any candy they choose, ex. Three types of Hershey kisses, different types of Sour Patch Kids, etc. It is important to watch the students and make sure they are not eating the candy. Although the analogy in this lab is helpful it is important for the teacher to roam the room to make sure students are understanding that each candy is an ISOTOPE and not a different type of element. It takes a few reminders for students to understand this, however once they do they enjoy the lab.

3. Explain – There is a PowerPoint attached as well as a Venn diagram handout. This should not be presented to students all at once. The PowerPoint can be broken up into different parts as an introduction to each section of the lesson. The exploration and elaboration activities can be used at the stopping point of the PowerPoint to make sure students are understanding the concepts presented to them. The Venn diagram should be helpful to students who have trouble differentiating between the subatomic particles.

4. Elaborate – It is up to the teacher to decide how much practice the students need based off how they are progressing. There are two practice handouts attached in this packet.

a. Isotopes and Ions handout – This handout offers many practice problems identifying the number of subatomic particles in a particular situation. It can be edited to do a few or all of the problems depending on how fast they are grasping the topic.

b. Average Atomic Mass handout – this handout offers practice atomic mass calculations. The assignment could be edited to include or eliminate the sample problem at the top of the page.

5. Evaluate – There is a quiz attached to check for a level of understanding on this lesson. This information would also be included in a unit test, unit review and remediation. There is also a Timeline Activity that could be used as an assessment or another group assignment. The Timeline Activity will help students to put together the scientists and what they contributed to science. This works as a great review activity, or can be edited as an assessment. It could also be used during lecture as notes for the students.

PWCS Standards Based Planning Process (continued)

Resources: o Warm-Up handout o PowerPoint o Venn Diagram Handout o Timeline Activity – Teacher will need photo copies of the “cards” included in this packet. Depending on how the teacher chooses to use this activity

(as a group assignment or assessment) will determine the number of copies needed. Students will also need construction paper, marks/crayone, glue and scissors.

o Isotopes and Ions Handout o Atoms Ions and Isotopes Activity – students each need a handout, a class set of marbles divided into the appropriate labeled bags and periodic tables

are also needed. This could also be done with different types of candy or simply cards with the information. However, the ability to ‘touch’ the subatomic particles is usually helpful to students.

o Average Atomic Mass Handout – students will need calculators o Atomic Mass of Candium – Peanut M&M’s, plain M&M’s and Skittles are needed, one large bag of each is usually sufficient. Teacher will also

need a class set of balances as well as containers for the candy. o Atomic Theory Quiz

Reflection: Based on data, how do I refine the learning experiences and/or the assessment?

Analysis of Data – The assessment should provide a good understanding of students weaknesses and strengths within the lesson. During the lesson there will also be periodic verbal and written checks done by the teacher to ensure understanding.

Immediate Implications – Based on the data analysis it is up to the teacher to determine how to further move along. The activities and handouts can be

edited to provide more practice for students. A word wall with important vocabulary could also be created to help prompt students and focus attention. Teacher guidance could also be used to help make flashcards if help is needed with the scientists’ contributions.

Future Planning – This lesson was developed in a scaffolded environment to ensure all students gain a strong understanding of the development of the atomic model. During each stage of the lesson the teacher needs to check for mastery. A successful understanding of this lesson will be built upon as previous knowledge in the next lesson.

Atomic Theory Warm-Up

1. Write a paragraph or draw a picture of what the word “Atom” means to you.

2. What is an ion?

3. What is an isotope?

Atomic Theory Warm-Up

1. Write a paragraph or draw a picture of what the word “Atom” means to you.

2. What is an ion?

3. What is an isotope?

SOL CH.2 a, b, i: The student will demonstrate an understanding of the development of the current atomic model

ENGAGE PHASE

Name: ____________________________________ Class Period: ______ Date: ________________

Naming Atoms, Ions, and Isotopes Introduction: Atoms are composed of three different particles – protons (p+), neutrons (n0), and electrons (e-). The identity of the atom is determined by its number of protons. For example, an atom with 1 proton in its nucleus must be hydrogen (atomic number = 1). Similarly, an atom with 10 protons in its nucleus must be neon (atomic number = 10). Every atom of a particular element contains the same number of protons. Atoms can gain or lose electrons to form ions. A neutral atom will contain the same number of protons (+ charges) and electrons (- charges). When an atom loses electrons, it forms a cation – a positively charged ion. When an atom gains electrons, it forms an anion – a negatively charged ion. Atoms of the same element can have different numbers of neutrons. These are called isotopes and they have different mass numbers. To determine the mass of an atom or isotope, simply add up the number of protons and neutrons present in the nucleus of the atom.

Pre-Lab Questions: 1. Write the element symbol for the following atoms: a) 6 protons, 6 neutrons, 6 electrons _____________ b) 18 protons, 20 neutrons, 18 electrons _____________ c) 3 protons, 4 neutrons, 3 electrons _____________ 2. Write the isotope name for the following atoms: a) 8 protons, 8 neutrons, 8 electrons _____________ b) 15 protons, 16 neutrons, 15 electrons _____________ c) 30 protons, 36 neutrons, 30 electrons _____________

3. Write the symbol for the following ions: a) 3 protons, 4 neutrons, 2 electrons ______________ b) 12 protons, 12 neutrons, 10 electrons ______________ c) 16 protons, 16 neutrons, 18 electrons ______________

1. At each lab station is a bag labeled A-R. Each bag contains varying amounts of: protons (black marbles), neutrons (blue marbles), and electrons (number written on the bag). 2. For each bag, record the number of protons, neutrons, and electrons in the Data Table. 3. Using these values and the periodic table, complete the remaining columns and determine the atom/ion

symbol.



EXPLORE PHASE

Ex.// 39 19

K

# of protons = atomic number (unique to each element) # of neutrons = mass number - # of protons # of electrons = # of protons (if atom is neutral)

6

C carbon 12.011

element name

atomic number

atomic mass

element symbol

Ex.// 39 19

K+

Ex.// Potassium - 39

Bag # of protons # of neutrons # of electrons Element Name Mass Number Symbol for

Atom or Ion

A 1 1 1 Hydrogen 2 2H

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

Atomic Mass of Candium Purpose: To analyze the isotopes of candium, and to calculate the atomic mass. Procedure:

1. Obtain a sample of each of the 3 known isotopes of the newly discovered element “candium” 2. Separate the three isotopes into groups labeled: A (peanut M&Ms), B (plain M&Ms) and C (Skittles). 3. Measure and record the total mass of each isotope sample (all the pieces). 4. Count and record the number of particles in each isotope sample. 5. Add across each row to determine the total mass of all three isotopes, and total # of particles 6. Use this information to complete the rest of the table.

Isotope A:

Isotope B:

Isotope C:

Total

Total Mass (g)

Number of Particles, (n)

Average Mass of each Particle (g) (total mass / # of particles)

Relative Abundance, RA (n / total # particles)

Percent Abundance (RA x 100%)

7. Use the above data and calculations to complete the following table. Reference your atomic mass handout

for a sample problem.

Name __________________________ Date ____________ Class: _________

Relative Abundance x Average Mass (g) = Relative Mass (g)

Isotope A: _________

Isotope B: _________

Isotope C: _________

Candium Average Atomic Mass =

Analysis:

1. Explain the difference between percent abundance and relative abundance. 2. What is the result when you total the percent abundances? The individual relative abundances?

3. Explain any differences between the atomic mass of your candium sample and that of your neighbor. Explain why the difference would be smaller if larger samples were used.

4. A sample of iron is 25.4% iron-55, 50.2% iron-56, and 24.4% iron-57. Determine the average atomic mass of the sample of iron. Show your work.

PowerPoint Presentation Please see attached powerpoint presentation titled “Atomic Theory Notes” to edit and/or present.


EXPLAIN PHASE


Slide 1

Atomic Theory

Slide 2

Smallest particle of an element w/ properties of that elementAbout 90 natural elementsCombine to form compounds

Atoms elements compounds

Slide 3

460 �– 370 BC: Democritus

�“atomos�” (indivisible & indestructible)Greeks believed in 4 basic elementsAccepted for 2000 years

Slide 4

Law of Conservation of Matter

Matter is neither created nor destroyed

Slide 5

Law of Definite Proportions

A compound always contains elements in a certain, definite proportion & no other combinationsEx.

H2O COHCl

Slide 6

Law of Multiple ProportionsElements may combine in more than one proportion forming different compoundsLed to the atomic theory

Slide 7

1. all matter is composed of atoms which are indivisible2. all atoms of the same element are alike, atoms of different elements are different3. Compounds are formed when atoms of different elements combined in fixed proportions4. Chemical reactions involve a rearrangement of atoms

Slide 8

Discovers proton using cathode ray tube & noticing that rays traveled in opposite direction of cathode (-)Mass is 1840x�’s that of an electron

Slide 9

Discovered electron using cathode ray tube where flow goes from cathode (-) to anode (+)Millikan in 1916 found mass(1/1840 x�’s mass of H atom) & charge(-1)

Slide 10

Slide 11

Discovers a condensed core w/ gold foil experimentCalled it the �‘nucleus�’ & composed of protons & neutronsModel known as �“Nuclear Atom�”

Slide 12

Slide 13

Discovers subatomic particle w/ no chargeaka NeutronMass nearly equal to proton (slightly larger)

Slide 14 Protons

PositiveSame as atomic number

ElectronsNegative

Outside nucleus1/1840 mass of proton

NeutronsNeutral= atomic mass �– atomic number

Subatomic Particles

In nucleus

Mass = 1840x�’s electron

Same as atomic number in a neutral atom

Slide 15

Mass # = #protons + # neutrons

Mass # for element & # neutrons may vary

Isotopes = different # of neutrons

Ex.

14C 6 p+, 8no

12C 6 p+, 6no

Slide 16

Increase/decrease in # of electrons

In atom:

Protons = electrons

Ex.

Na

11p+, 11e-

Na+

11p+, 10e-

Slide 17

Found using mass spectrometerBased on average of relative abundance of isotopes of the elementMeasured in amu�’s (1/12 of a carbon atom)

Slide 18

Number of stable isotopes

% of each isotope

Mass of each isotope

I usually draw out a pie on the board. Isplit it into three sections and give a %and a �‘mass�’ for each section. Then Iask the students �“if 30% of the pie ispumpkin, 60% of the pie is apple and10% of the pie is blueberry, what is themass of the entire pie?�”

Neeutrons

Subatomic Par

rticle Ven

Protons

Name: Class P

nn Diagr

_________

Period: ____

ram

Ele

__________

___ Date

ectrons

___________

e: ________

_________

_________

Isotopes and Ions Handout

1. What is the Atomic Number of the following:a) Beryllium b) Gold c) Copper

2. What is the atomic mass of the following:a) Arsenic b) Tin c) Tungsten

3. How many protons are present in each of the following elements?a) Polonium b) Barium c) Manganese

4. How many electrons are present in each of the following elements?a) Osmium b) Sodium c) Magnesium

5. How many neutrons are present in the following elements?a) Silver b) Calcium c) Platinum

6. Fill in the table below:

Element SymbolAtomicNumber

MassNumber

Number ofProtons

Number ofNeutrons

Number ofElectrons

Neutral,Isotope,

positive ion ornegative ion

Carbon 6 12 Neutral6 8 6

Oxygen 8 8 10Mg 12 24 10

Uranium 92 238 NeutralU 143 92 Isotope

Helium 2 4 2Na 11 12 10

Chromium 24 52 2+ ionCl 17 18 1 ionHg 80 201 Neutral

Aluminum 13 14 3+ ionNe 20 10 Neutral

1 2 Isotope1 0 1+ ion

Phosphorus 15 16 15Li 4 2 Neutral

Potassium 19 20 19Fe 26 30 23

7. Express the element "Phosphorus" in neutral and ionic form. Explain the difference and how you can tell.



ELABORATE PHASE

Isotopes and Ions Handout KEY

1. What is the Atomic Number of the following:a) Beryllium 4 b) Gold 79 c) Copper 29

2. What is the atomic mass of the following:a) Arsenic 74.92 b) Tin 118.71 c) Tungsten 183.84

3. How many protons are present in each of the following elements?a) Polonium 84 b) Barium 56 c) Manganese 25

4. How many electrons are present in each of the following elements?a) Osmium 76 b) Sodium 11 c) Magnesium 12

5. How many neutrons are present in the following elements?a) Silver 61 b) Calcium 20 c) Platinum 117

6. Fill in the table below:

Element SymbolAtomicNumber

MassNumber

Number ofProtons

Number ofNeutrons

Number ofElectrons

Neutral,Isotope,

positive ion ornegative ion

Carbon C 6 12 6 6 6 NeutralCARBON C 6 14 6 8 6 ISOTOPEOxygen O 8 16 8 8 10 2 ION

MAGNESIUM Mg 12 24 12 12 10 2+ IONUranium U 92 238 92 146 92 NeutralURANIUM U 92 235 92 143 92 IsotopeHelium He 2 4 2 2 2 NEUTRALSODIUM Na 11 23 11 12 10 1+ ION

Chromium Cr 24 52 24 28 22 2+ ionCHLORINE Cl 17 35 17 18 16 1 ionMERCURY Hg 80 201 80 121 80 NeutralAluminum Al 13 27 13 14 10 3+ ionNEON Ne 10 20 10 10 10 Neutral

HYDROGEN H 1 2 1 3 1 IsotopeHYDROGEN H 1 1 1 0 0 1+ ionPhosphorus P 15 31 15 16 15 NEUTRALLITHIUM Li 3 7 3 4 2 NeutralPotassium K 19 39 19 20 19 NETURAL

IRON Fe 26 56 26 30 23 3+ ION

7. Express the element "Phosphorus" in neutral and ionic form. Explain the difference and how you can tell.

Average Atomic Mass

Determine the average atomic mass of the following mixtures of isotopes.

1. 80% 127I, 17% 126I, 3% 129I

2. 50% 197Au, 50% 198Au

3. 15% 55Fe, 85% 56Fe

4. 99% 1H, 0.8% 2H, 0.2% 3H

5. 95% 14N, 3% 15N, 2% 16N

6. 98% 12C, 2% 14C

EXAMPLE: A sample of cesium is 75% 133Cs, 20% 132Cs, and 5% 134Cs, what is the average atomic mass of cesium? ANSWER: .75 x 133 = 99.75 .20 x 132 = 26.4 .05 x 134 = 6.7

Total = 132.85 amu


Average Atomic Mass KEY

Determine the average atomic mass of the following mixtures of isotopes.

1. 80% 127I, 17% 126I, 3% 129I

126.86

2. 50% 197Au, 50% 198Au

197.5

3. 15% 55Fe, 85% 56Fe

55.85

4. 99% 1H, 0.8% 2H, 0.2% 3H

1.012

5. 95% 14N, 3% 15N, 2% 16N

14.07

6. 98% 12C, 2% 14C

12.04

EXAMPLE: A sample of cesium is 75% 133Cs, 20% 132Cs, and 5% 134Cs, what is the average atomic mass of cesium? ANSWER: .75 x 133 = 99.75 .20 x 132 = 26.4 .05 x 134 = 6.7

Total = 132.85 amu

Atomic Theory Quiz

1. The ________________ is the smallest Unit of matter. 2. Atoms form __________________, which in return can form compounds. 3. The scientist that discovered the “atomos” and found it to be indivisible and indestructible was

a. Dalton b. Proust c. Democritus d. Rutherford

4. JJ Thompson discovered the electron using which instrument? a. Spectrometer b. Cathode Ray Tube c. Gold Foil d. Periodic Table

5. Using his gold foil experiment Rutherford discovered the a. Nucleus b. Electron cloud c. Electron d. Proton

6. Fill in any missing cells the chart:

Subatomic Particle Proton Electron Charge neutral Location nucleus Mass Slightly larger than a

proton

7. Fill in any missing cells in the chart:

NAME SYMBOL ATOM # MASS # #p #n #e Iso/Ion/Neu Ca 20 40 Bromine 35 36 -1 Ion Te 52 79 K 19 20 18

8. Calculate the Atomic Mass for 32% Chromium-52, 8% Chromium-53 and 60% Chromium-51.

SOL CH.2 a, b, i: The student will demonstrate an understanding of the development of the current atomic model Name: ____________________________________

Class Period: ______ Date: ________________

EVALUATE PHASE

Timeline Activity/Assessment

With a partner, create a timeline including ALL of the following items.You will be cutting out each square and gluing them to a colored pieceof paper. This is a timeline, so be sure to draw your "line" and includearrows/symbols to connect any additional facts. You must include the"wild" cards with a piece of information that was not here that you findto be important.

DemocritusModel known as�“Nuclear Atom�”

Discoverssubatomic

particle w/ nocharge

Joseph Proust

Chemicalreactions involve arearrangement of

atoms

Mass nearly equalto proton (slightly

larger)

EugeneGoldstein

Discovers protonusing cathode raytube & noticingthat rays traveled

in oppositedirection ofcathode ( )

Found �‘nucleus�’& said it wascomposed ofprotons &neutrons

James Chadwick

Discovers themass is 1840x�’s

that of anelectron

ErnestRutherford

Millikan in 1916found

mass(1/1840 x�’smass of H atom) &

charge( 1)

Discovers acondensed corew/ gold foilexperiment

Law of DefiniteProportions

�“atomos�”(indivisible &indestructible)

JJ Thomson

compound alwayscontains elements

in a certain,definite

proportion & noother

combinations

John Dalton *WILD*Law of

Conservation ofMatter

Discoveredelectron using

cathode ray tubewhere flow goesfrom cathode ( )to anode (+)

Atomic theoryMatter is

neither creatednor destroyed

*WILD*

all matter iscomposed of

atoms which areindivisible

all atoms of thesame element arealike, atoms of

different elementsare different

*WILD* LavoisierLaw of MultipleProportions

Accepted for2000 years

Led to theatomic theory

Compounds areformed when atomsof different elementscombined in fixed

proportions

elements maycombine in more

than one proportionforming different

compounds

Documents

Atomic Theory Lesson - Weeblycsouders.weebly.com/uploads/6/3/7/8/6378620/atomic_theory_lesson… · Atomic Theory C. Souders – Battlefield Standard of Learning SOL CH.2 a, b, i: