Student Number ___________________________ Hour _________

THE AMAZING WORLD OF

THE

ATOM

“Ohhhhhh….Look at that, Schuster…Dogs are so cute when they try to comprehend quantum mechanics.”

Another case of too many scientists and not enough hunchbacks.

Atom, Page 2

UNIT OBJECTIVES

1. LIST some scientists and IDENTIFY some of their experiments and reasoning that lead to an atomic theory.

2. CONSTRUCT a model of an atom according to the Bohr atomic model and INFER from the atomic model the relative relationship of matter to space in an atom.

3. EXPLAIN the need for various models of the atom.

4. In the laboratory, OBSERVE and CORRELATE spectral emission of light to quantum jumps of electrons.

5. From the laboratory, COMPARE and CONTRAST spectral and other electromagnetic emissions from various sources.

6. RESEARCH and DESCRIBE examples of how photon emission is used as a tool.

7. RELATE photon energy to the color of light emitted.

8. DEFINE atom, element, molecule and compound.

9. DISTINGUISH between protons, neutrons, and electrons in terms of their location, relative masses (size), charges and functions in an atom.

10. COMPUTE the number of protons, neutrons and electrons in an atom; also the atomic number and mass.

11. STATE how isotopes of an element differ and APPLY the concept of isotopes.

12. APPLY rules for electron arrangement in the filling of electron orbitals.

13. CORRELATE the position of elements on the periodic table with their electron arrangement and atomic structure.

14. INTER­CONVERT moles, grams and Avogadro’s number.

Atom, Page 3

Early models for salt, water, and iron atoms.

What Is An Atom? I ­ Earliest Models Of The Atom

~ 400 B.C.

A. Democritus, a Greek Philosopher, came up with the idea of the atom by ___________ about it.

B. ___________ hypothesis was that all things were made up of small, __________ particles which he called _____________.

384­322 B.C.

A. Aristotle rejected Democritus’ theory.

B. He believed all things were _________ divisible and composed of only one substance called _________. This idea held throughout the middle ages of Europe.

1700’s

A. Charle Coulomb showed the ___________ between the amount of electric force that two ___________ particles exert upon each other and the _______________ separating them.

1. Laws of _____________ and repulsion (opposites attract, likes repel) 2. As distance increases the ______________ force decreases.

B. Antoine Lavoisier studied ____________ systems and _______________ reactions.

1. Law of __________________ of matter. a. He found that in ordinary chemical reactions, matter can be ___________

in many ways, but it cannot be created or destroyed.

C. Joseph Proust observed that specific substances always contain __________ in the same _________ by mass. This came to be known as the law of definite _______________.

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II ­ Smaller Than The Smallest

1800’s

A. John Dalton (1803) combined the work of Lavoisier and Proust to help him develop his atomic theory.

1. He hypothesize that all ___________ is made up of very small particles called _________. Dalton’s ideas were similar to those of ______________.

2. Dalton believed that atoms of different ____________ were not the __________, and that __________ of one element were exactly __________.

3. Dalton also stated that atoms can _________ with other atoms in ___________ ratios to form ____________.

4. The _______ of ___________proportions. a. Because atoms cannot be ___________, these ratios can be expressed in

small _________ numbers.

B. Avogadro, in 1811, suggested that equal volumes of different gases, under the same conditions (pressure, temperature) contain same number of atoms.

C. Mendaleev developed the periodic table of elements, which finalized the belief in the existence of atoms.

D. In 1896, Henri Becquerel accidentally discovered that _____________ ores emit invisible ________ that fog photographic plates.

E. Marie Curie and her husband, Pierre, found that these rays came from the _______and were _____________ than the atom. Marie was the first to use the term ___________________.

1. Becquerel and the Curies put an end to ____________ idea that the atom was ______________.

2. She also discovered two new radioactive elements, _________________ and ______________.

F. J.J. Thomson developed his model of the atom when he discovered that atoms are divisible.

1. In 1897, he used the cathode ray tube. In a vacuum tube a luminous beam flowed between the negative (___________) and positive (_____________) terminals of a high voltage supply.

2. Using the cathode ray tube with magnets and electrical plated he discovered that the cathode ray was made up of negatively charged particles.

a. He calculated these particles to have a mass __________ as much as a hydrogen atom, the lightest known atom.

b. He called these sub­atomic particles _________.

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Demonstration Notes:

What can we conclude from our observations of the cathode ray tube?

Describe and diagram J.J. Thomson’s model of the atom.

The Story So Far

DEFINITIONS

Element ­ A type of ____________ that cannot be ____________ broken down.

Atom ­ The __________ particle of an ___________ that posses the____________ of that element.

Molecule ­ A ____________ made up of two or more __________.

Compound ­ Two or more ____________ combined by _____________bonds.

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1 + 1 =? Procedure:

1. Pour water into both graduated cylinders. Rinse well. Pour out the water and completely dry off the outside of each cylinders.

2. Accurately measure the mass of each graduated cylinder. Mass of grad cylinder #1 ___________ Mass of grad cylinder #2 ___________

3. Accurately measure 10.0 mL of solution “A” into graduated cylinder #1 and 10.0 mL of solution “B” into graduated cylinder #2. What is the appearance of each solution?

Appearance solution “A” ___________ Appearance solution “B” ___________

4. Accurately measure the mass of each graduated cylinder and solution. Mass of grad cylinder #1 and solution “A” ___________ Mass of grad cylinder #2 and solution “B” ___________ Mass of solution “A” alone ___________ Mass of solution “B” alone ____________

In a short while, you will mix solutions “A” and “B”. Predict what the volume of the “A” and “B” mix will be: ______________ . Predict what the mass of the “A” and “B” mix will be ( minus the graduated cylinder): ____________________ .

5. Pour the entire contents of grad cylinders #1 into grad cylinder #2. Note any changes in the appearance of the solutions.

6. Accurately complete the following measurements: Mass of grad cylinder #2 with “A” and “B” mix ___________ Mass of solution “A” and “B” mix alone ____________ Volume of “A” and “B” mix ____________

Conclusion:

1. What changes did you observe?

2. What evidence is there that a chemical reaction took place?

3. Does the law of conservation of matter apply to mass or volume? WHY?

4. Explain why your predictions did or did not agree with the actual masses and volumes.

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How BIG is small? Introduction: Oleic acid is a chemical that is less dense than water, which means it will float on the surface of the water. The “oil slick” that forms will be one molecule thick.

This unique characteristic and some mathematics will allow us to study the size of a molecule. When a single drop of a 0.1% oleic acid solution is placed on the water surface, it will form a cylinder one molecule high.

This experiment requires quantitative measurements. Be sure to read the measuring device to the correct number of decimal places and to include the correct units.

Problem:

Procedure:

Data: FROM THE LAB

1. How many drops of water are in one mL? ________ drops 2. What is diameter of the oleic acid

“oil slick”? ________ cm

FROM THE COMPUTER

3. The volume of oleic acid in one drop is ________ mL

4. The area of the “oil slick” produced when a single drop oleic acid solution is placed on the water surface? ________ cm

2

5. The height of the “oil slick” cylinder is... ( Height = Volume / Area ) ________ cm

Conclusion:

1. What does the value of “height” represent?

2. What is the shape of the "oil slick"

3. Write a short statement about the size of an atom when compared to the size of an oleic acid molecule.

Atom, Page 8

III – The Sub – Atomics

1900’s

A. Max Planck, in 1900, introduced the idea of quanta to explain the _________ of light emitted by certain heated objects.

1. _________ is not given off continuously, but in small packets called __________.

B. In 1905, Albert Einstein broadened Plank’s idea to explain __________ effect. 1. Einstein mathematically determined that _______ was made up of

_____________ that had discrete energies. 2. He called these particles __________. Until that time, light was thought to be

only __________ carried in the form of _________.

C. Robert Millikan, in 1909, calculated the ____________ on the electron in his “oil drop” experiment.

1. Electrons were transferred from the atomizer to the ________________. The _______________ charged particles fell through a vacuum under the influence of _______________.

2. Millikan adjusted the voltage on the plates to ___________ the pull of gravity. He found that each droplet had a different charge, but all the charges were a ___________ of one small charge. He assumed that small charge to be the charge of one ___________.

Telescope

Charged oil drop

Electrical force

Gravitational force

Apparatus similar to the one used by Millikan to determine the charge on an electron.

Atom, Page 9

1900’s Continued

D. Ernest Rutherford developed his atomic model from observations made in his gold­ foil experiment.

1. Rutherford found that ______ of the invisible rays discovered by the Curies had a ____________ charge, was extremely __________, and moved very _________. He called this an __________ particle.

2. Rutherford _____________ a thin piece of gold with alpha particles. a. The __________ of particles passed _____________ through the

foil. This indicated to him that the atom was mostly ____________ space.

b. Some particles did however hit something in the foil. From the fact that the alpha particle is ____________ charged and the _____________ pattern the particles produced, Rutherford stated that in the _____________ of each atom is a dense _____________ that is ______________ charged.

3. In 1911, Rutherford developed an ___________ model that had a ______________ charged nucleus and was surrounded by _________.

4. Rutherford also predicted the existence of ___________ particle in the nucleus.

From your “Black Box” and “Bowling for Atoms” investigations, what are three things you can determine about an object without directly seeing it?

Atom, Page 10

Bowling for Atoms Procedures:

A 60 cm figure has been measured off an the floor similar to the diagram below. Obtain between 4 – 8 spheres from the supply table. Measure the diameter of a target sphere. Divide the following work between you and your laboratory partner. One will roll a ‘bullet’ sphere towards the target spheres without looking!!!!! The other partner will count the number of collisions and the number of tries. 100 tries will be adequate. Switch roles after one partner has had 50 attempts. Remember no cheating.

If the sphere hits the sides of the 60 cm mark, it counts as a miss. If the sphere hits one, two or three balls it counts as only one hit. When a hit occurs the counter partner must replace the ‘hit’ sphere in approximately the same location. The release distance is approximately 60 cm.

Once you have completed the 100 attempts, count the number of hits. 7you now can enter your data into the computer and mathematically determine the size of the target spheres.

O = Target sphere X = Bullet sphere

O O O O O (60 cm)

X

Hits Misses

Diameter of Sphere: Measured _____________ Calculated _______________

Atom, Page 11

Overhead Black Box PROCEDURE : Follow the directions on the computer screen in order to determine some

of the properties of the hidden object.

PREDICTED CORRECT

Pizza Black Box PROCEDURE: Using your sense of touch and hearing determine some of the

properties of the object(s) located in the box.

PREDICTED CORRECT

Atom, Page 12

1900’s continued

E. In 1913, Neils Bohr combined the work of Plank (spectral analysis) and Rutherford (positively charged nucleus) to develop his atomic model.

1. Bohr’s model had a positively charged _____________ surrounded by ______________ that were in defined _____________ around this nucleus.

2. The distance of each _________ from the nucleus was ___________. 3. An electron could ____________ orbitals if was sufficiently ______________

with incoming energy. 4. With his model, he could calculate the spectral lines for ___________.

a. This was because he predicted that a ___________ of light energy was ______________ each time an electron fell from one orbital to another.

b. The ______________ of the photon was determined by how far the electron _________ to its original __________.

Diagram a Bohr model of a hydrogen atom. Include and label the proton, neutron, nucleus, electron and orbitals. Include your calculations for the scale model of the atom.

Atom, Page 13

FLAMES AWAY! Accurately color your observations using the spectroscope. Label each element, and the high and low energy ends of the white light spectrum.

Spectrum of white light Element Name _________________

Element Name ___________________ Element Name _________________

Element Name _____________________ Element Name _________________

Element Name _____________________ Element Name _________________

Element Name _____________________ Element Name _________________

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Wavelength 4 5 6 7

Atom, Page 14

Properties of Sub­Atomic Particles Electrons Protons Neutrons 1._______________ 1._______________ 1._______________ _______________ ________________ _______________

2._______________ 2._______________ 2._______________ _______________ _______________ _______________

3._______________ 3._______________ 3._______________ _______________ _______________ _______________

4._______________ 4._______________ 4._______________ _______________ _______________ _______________

5._______________ 5._______________ 5._______________ _______________ _______________ _______________

6._______________ 6._______________ 6._______________ _______________ _______________ _______________

Atomic Number : 1.___________________________________ 2.___________________________________ 3.___________________________________

Atomic Mass Number :

A ____________ number closest to the atomic mass. It is the ________ of the number of ________ and __________ in the nucleus of the atom.

Atomic Number = Number of ___________

Number of Protons = Number of ______________

Number of Neutrons = Atomic Mass Number Minus the Number

of __________

Atom, Page 15

Beanium You are about to undertake an experiment to ascertain the atomic mass of the recently discovered element, beanium. Research has verified the existence of three isotopes of beanium which will be called: white­beanium, red­beanium, and black­beanium. These isotopes are found in nature in the same percentage of occurrence as in the sample with which you will be provided.

DATA TABLE:

MASS OF PERCENT SAMPLE BEAN NUMBER MASS OF SINGLE BEAN ABUNDANCE NUMBER TYPE OF BEANS BEANS ATOM OF ISOTOPE

________ BLACK _________ ______ g ______ g ______ % RED _________ ______ g ______ g ______ % WHITE _________ ______ g ______ g ______ % TOTAL _________ _______ g __100__ %

ATOMIC MASS OF beanium _____________

QUESTIONS:

1. What is the basic atomic difference between isotopes of the same element, other than atomic weight?

2. Why are atomic masses on the periodic table not listed in whole numbers?

3. Aluminum has an atomic weight of 27 (rounded off), but isotopes have mass numbers of 24, 25, 26, 28, 29, and 30. Why are they considered to be aluminum atoms?

Atom, Page 16

Notice! You will notice, the atomic mass number is the same as

the Molar mass or Gram formula mass number.

Atomic Mass The ______________ average of the masses of the ___________ of that element.

Isotope Atoms that have the ___________ number of ____________ but _________________ numbers of _____________.

Mass Number Mass Number

30 __ __ X X

15 __ __ (isotope) Atomic Number Atomic Number

Periodic Trends in Atomic Size

Using the above figure make the following two generalizations.

1. Within a group (column) atomic size generally tends to _______________ when going from top to bottom. A result of increasing the number of principal _______________ levels.

2. Within a period (row) atomic size generally tends to _______________ when moving left to right. A result of the effective ______________ charge acting on its electrons.

On yourPeriodic Table “A” mark the trends using arrows, with the arrow pointing in the direction of increasing size. Be sure to include the legend in the “KEY :” area of the chart.

Atom, Page 17

IV ­ Wave Mechanical Model

A. In 1924, Louis de Broglie proposed that _____________ have the properties of __________.

B. Werner Heisenberg developed the ______________ principle.

The uncertainty principle when applied to the electron states that it is inherently _______________ for us to know simultaneously both the exact _________________ of the electron and its exact ________________ in space.

C. Erwin Schrodinger, in 1926, proposed an equation that incorporates both the _______________ and ________________ behavior of the electron. This is known as a wave function.

D. From the work of Broglie, Heisenberg, and Schrodinger we have the wave mechanical model of the atom.

1. Electrons behave like ___________. 2. Electron in atoms have ____________ energies. 3. Electrons are arranged in certain energy __________ (orbitals) 4. Electron _________ can be described as an electron

probability ______________.

Why was the wave mechanical model of the atom developed?

Because electrons behave as waves they move in different patterns. Draw and label the “s” and three “p” orbitals here:

Atom, Page 18

Electron Arrangements Elements are arranged in the periodic table according to _______________ number. The atomic number corresponds not only to the number of ______________ in the nucleus of the neutral atom, but also to the number of ______________ in that atom.

The arrangement of electrons in an atom is called the _________________ configuration

All things in nature seek to be at the ______________ possible energy level. Think of objects falling from the sky seeking the lowest potential energy of the Earth’s surface. The same is true for ________________. The most ____________ , or ground, electron configuration of an atom is that in which the _____________ are in the ____________ possible energy states.

The orbitals of an atom are ____________ in order of ________________ energy.

In the Quantum Mechanics model of the atom, the Principal _______________ levels (n=1, 2, 3, etc.) of electron orbitals are divided into ____________ based on the energy an electron would release if it should fall to the ____________ state. Each energy _____________ corresponds to a different electron cloud ____________, denoted by the letters ______ (spherical shaped clouds), ______ (dumbbell shaped clouds), ________ and ________ (complex shaped clouds). The cloud ______________ is where there is a high ______________ of finding an electron.

Electron Arrangement Rules 1. Electrons enter the ______________ energy level first. (Aufbau Principle)

2. ____________ orbital (sublevel) has more than _________ electrons. (Pauli Exclusion Principle)

3. __________ electron ___________ takes place until all orbitals (sublevels) in an energy level are half filled. (Hund Rule)

4. ___________ filled or ____________ filled levels have extra stability.

Atom, Page 19

Sample of electron filling (electron configuration)

Electron­dot symbols are a ____________ way of showing the ________________ electron shell of an atom. The electron­dot symbol for an element consists of the chemical __________________ for the element plus a __________ for each outer shell (valence) electron. Dots are placed in __________ “regions” around the atomic symbol: the top, the bottom, and the left and right sides. Each of these regions can accommodate _________ electrons.

If you understand how the periodic table is organized, it is not necessary to memorize the order in which __________ fill. You can write the electron configuration of an element based on its __________ in the periodic table.

Marking your periodic table on the “Eight Families of Elements”

1. Mark the generalized electron configuration for each family. 2. Mark the generalized electron­dot symbol for each family.

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Atom, Page 20

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Electron Configuration

4s Element Name:

3p

3s

2p

2s

1s

E Dot

Atom, Page 21

LOCATING AN ELECTRON IN AN ATOM

DATA TABLES:

A. B. C. D. E.

Number of Circular Area

Increment

Average Radial distance of

Area Increment From Bulls­eye

Area of Increment

Number of Dots in Area

Increment

Dots in Unit Area x 10

1 R1 = 0.5 cm 3 cm 2

2 R2 = 2.0 cm 25 cm 2

3 R3 = 4.0 cm 50 cm 2

4 R4 = 6.0 cm 75 cm 2

5 R5 = 8.0 cm 100 cm 2

Area Increment

Your Drop Count

Partner's Drop Count

Lab #3 Drop Count

Lab #4 Drop Count

F.

Total

1

2

3

4

5

Atom, Page 22

Area

G.

Average

H.

Dots Per Unit Area x 10

1

2

3

4

5

Questions: 1. Which of the graphs show the best shape of the curve when compared to the graph of

the Bohr curve? Explain why.

2. When you drop a dart on the target, can you predict precisely where it will strike? Can you predict an area within which the dart is likely to strike? How are your responses to these questions analogous to the problem of locating an electron about the nucleus of a atom?

3. What is an orbital and how many (maximum) electrons may an orbital contain?

Atom, Page 23

Avogadro Meets Mr. Mole By doing some quick mathematics with the _________ of protons, neutrons and electrons, chemists were able to calculate that one __________ of atoms contains approximately ____________ atoms in it. This number, 6.02 X 10

23 , is called

_______________ Number.

The same is true for molecules, there are _______________ molecules in a mole. (Be careful not to confuse moles (fuzzy creatures) with molecules!)

These _______________ can be written as: ____________________ or __________________

Avogadro and You Solve the following challenges showing ALL of your WORK using the Picket Fence.

1. How many atoms are in 3 moles of calcium?

2. How many atoms are in 6.5 moles of Na?

3. How many molecules are in 1.8 moles of strontium nitrate?

4. How many atoms are in 50 grams of sodium?

5. How many atoms are in 8.6 grams of beryllium?

6. How many atoms are in 55 kilograms of fluorine?

7. How many molecules are in 24 g of CuSO 4 ?

Atom, Page 24

Practice with the Atom For each scientist describe their model and/or experiment, the information learned, and what they contributed to the atomic model accepted today. Draw their model of an atom.

1. Democritius

2. Dalton

3. Thomson

4. Rutherford

5. Bohr

6. Wave­mechanical model

7. ­ 21. Match the properties of sub­atomic particles on the right with the particles on the left, by placing the correct five letters after each particle. Neutron Electron Proton a. gives the physical properties

_______ ________ ________ (melting pt., density) to the atom _______ ________ ________ b. gives the chemical properties _______ ________ ________ (how it joins with other atoms) to the atom _______ ________ ________ c. negative charge _______ ________ ________ d. neutral charge

e. nucleus f. one mass unit g. positive charge h. separates the protons to stabilize the nucleus i. surrounding cloud j. zero mass units k. 10 ­24 grams

Fill in the chart below. l. 10 ­28 grams

Element Number of Protons Number of Electrons Number of Neutrons

Sodium 22. 23. 24.

Si­30 (silicon isotope) 25. 26. 27.

Bromine 28. 29. 30.

Neon 31. 32. 33.

34. Describe the atom in your own words.

Use the diagram on the next page to answer questions 35 through 39.

Electromagnetic radiations are photons traveling in waves at the speed of light. The wave length is the distance from the crest of one wave to the crest of another. Frequency is the number of waves that pass a given point in one second (waves/sec.).

Atom, Page 25

35. The electromagnetic spectrum shows the relationship between: a. the mass of light and its force b. the forces caused by light and the wavelength c. the amount of energy and wavelength d. the electrical power and strength of energy e. gamma and radio waves only

36. Which of the following occurs as energy of electromagnetic radiation increases? a. wavelength increases d. frequency decreases b. wavelength decreases e. both b and c are correct c. frequency increases

37. Of the colors listed below which one has the highest energy? a. blue d. red b. green e. yellow c. orange

38. When an excited electron drops from the 4th orbital to the 2nd orbital, a photon that exhibits the color green is emitted. What would the color be of a photon emitted when an electron drops from the 3rd to the 2nd orbital? a. blue d. yellow b. green e. white c. purple

39. Explain why your choice is correct.

The chart below shows a set of "energy levels" that an electron in molecule A can occupy. The value of the energy in each level is shown to the right. An electron can move from one level to the next in two ways:

Energy levels E5 ­­­­­­­­­ 2.07 a) the molecule can absorb a particle of light called a "photon", E4 ­­­­­­­­­ 1.75 of just the right energy to lift the electron to a higher level. For E3 ­­­­­­­­­ 1.52 example, an electron in level 4 can be raised to level 5 if the E2 ­­­­­­­­­ 1.20 molecule absorbs a photon whose energy is 0.32 E1 ­­­­­­­­­ 0.60 b) the molecule can emit, or give off, a photon of just the right

energy necessary to lower an electron to another level. For example, an electron in level 4 can move to level 3 if the molecule emits a photon whose energy is 0.23.

Atom, Page 26

40. A sample containing many A molecules absorbs light, each photon of which carries 0.60 units of energy. As the light is absorbed: a) an electron moves from level 1 to level 2. b) an electron moves from level 2 to level 5. c) an electron moves from level 2 to level 1. d) an electron moves from level 4 to level 2.

41. A sample of molecule A emits light, each photon of which carries .32 units of energy. Which of the following statements best explains this observation?

a) an electron has moved from level 3 to level 2. b) an electron has moved from level 2 to level 3. c) an electron has moved from level 5 to level 4. d) an electron has moved from level 3 to level 2, or

from level 5 to level 4. 42. A sample of molecule A emits light whose photons each carry .92 units of energy.

As the light is emitted: a) an electron moves from level 5 to level 2. b) an electron moves from level 1 to level 5. c) an electron moves from level 1 to level 3. d) an electron moves from level 3 to level 1.

43. Suppose in a sample of molecule A, all of the electrons are in level 1. Based on the information in the chart, photons of how many different energies could be absorbed by the sample? a) 1 b) 2 c) 3 d) 4

44. As an electron moves from level 1 to level 3, the amount of energy : a) increases b) decreases c) stays the same d) changes by varying amounts of energy

Write the Electron Configuration Give the Electron Dot notation for the following elements. for the following elements.

45. Lithium 52. Oxygen 46. Calcium 53. Sodium 47. Fluorine 54. Krypton 48. Neon 55. Beryllium 49. Aluminum 56. Calcium 50. Potassium 57. Helium 51. Carbon 58. Tin

Answer the following.

59. How many electrons can an “S” cloud shape orbital hold?

60. How many electrons can the “P” cloud shape orbital hold?

61. What orbital would an electron want to enter first?

62. A “P” sublevel contains 3 electrons, how would these electrons be arranged?

63. What is the instrument used to show a bright line spectrum?

64. What is required for an electron to change orbitals?

65. What is released when an electron falls from a higher energy level (orbital) to a lower energy (orbital )?

66. What are three principles, which guide the electron configuration of an atom?

Atom, Page 27

Calculate the following. Please show your picket fence work!!

67. How many moles are in 5g of BaCO3?

68. How many grams are in 2.8 moles of NaCl?

69. How many molecules are in 3 moles of CO2?

70. How many atoms are in 2.2 g of CO?

71. How many molecules are in 4.8 moles of HCl?

72. A telescope was able to collect light from a far away star. The light was put through a

spectroscope to identify the elements of the star. Choose all elements found on the star by circling the element name.