Chapter Resource Files Electrons and Energy Levels 1 PDF

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just the outline and chapter resources...

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Content Vocabulary

Electrons and Energy Levels Directions: Explain the relationship between each set of terms on the lines provided. You must include the terms below in your answer.

1. electron dot diagram, valence electron

2. chemical bond, compound

3. valence electron, chemical bond

4. compound, valence electron

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Lesson Outline

Electrons and Energy Levels A. The Periodic Table 1. The periodic table organizes the chemical

.

2. Each block in the periodic table describes basic

of one

element.

3. The periodic table lists elements in order by

.

4. Elements in each 5.

have similar physical properties. are on the left side of the periodic table. are on the right side of the table. are located in a narrow stair-step region

between the metals and the nonmetals.

B. Atoms Bond 1. Most of the matter around you is made up of

that

include two or more different elements.

2. A(n)

is a force that holds atoms together.

3. Atoms contain

with a positive charge, with a neutral charge, and

with a negative charge.

a.

are the atomic particles that participate in chemical bonding.

b. The amount of energy an electron can have is a(n) c. Electrons closest to the nucleus have the

. energy;

electrons farthest from the nucleus have the

energy.

d. The maximum number of electrons in the first energy level, which is closest to the nucleus, is

. The maximum number of electrons

in the second energy level is

e. The

. electrons in an atom are involved in chemical

bonding. These electrons are less strongly attached to the

.

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Lesson Outline continued 4. A(n)

is an outermost electron that participates in

chemical bonding.

a. The number of valence electrons in an atom tells you how many an atom can form.

b. Each element in the same

in the periodic table has

the same number of valence electrons.

5. The

is a model that represents valence electrons in an atom as dots around the element’s chemical symbol.

a. To create an electron dot diagram, draw one dot for each electron in the atom, placing one dot on each of the

sides of the symbol

and then pairing additional dots.

b. The number of

dots in the electron dot diagram tells

you how many bonds an atom can form. 6. Many atoms are stable with

valence electrons. An atom

with at least one unpaired electron is

a.

.

atoms do not easily react with or form bonds with other atoms.

b. Group 18 includes the

; with the exception of helium, each of these gases have eight valence electrons and are stable.

c. Unstable atoms can become stable only by forming with other atoms.

d. Atoms tend to gain, lose, or share valence electrons until each atom has the same number of valence electrons as the

e. Stable atoms have

. pairs of valence electrons.

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Content Practice A

Electrons and Energy Levels Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once.

1. organized layout of elements 2. elements with similar properties

A. energy levels B. helium C. low-energy electrons

3. number of protons

D. periodic table E. neon

4. locations of electrons

F. group G. valence electrons

5. innermost electrons

H. atomic number I. chemical bonds

6. unpaired dots in electron dot diagram 7. force holding atoms together in compounds 8. the smallest atom 9. stable with two electrons 10. stable with ten electrons

J. hydrogen

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Content Practice B

Electrons and Energy Levels Directions: Answer each question in the space provided.

Electrons and Chemical Bonds Question 1. How are elements organized on the periodic table?

2. What are the three main classifications of the elements? 3. What is a chemical bond?

4. What determines an element’s atomic number?

5. Which electrons in an atom have the most energy, and which ones have the least? 6. Which electrons in an atom take part in chemical bonding, and what are they called? 7. What kind of diagram is used to show how many of these electrons an atom has? 8. What name is given to elements with eight outer electrons?

9. Which element belongs to this group, although it has only two electrons? 10. How many chemical bonds can a single atom of these elements form: hydrogen, carbon, nitrogen?

Answer

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School to Home

Electrons and Energy Levels Directions: Use your textbook to answer each question.

1. Elements chemically combine to create different compounds. A chemical bond is a force that holds atoms together. How does an electron’s distance from the nucleus impact chemical bonding?

2. The number of valence electrons in an atom indicates how many chemical bonds that atom can form. What is a valence electron?

3. Electron dot diagrams allow chemists to predict how many bonds an atom can form with other atoms. What would you notice about the dot diagram of an unstable element?

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Key Concept Builder

Electrons and Energy Levels Key Concept How is an electron’s energy related to its distance from the nucleus? Directions: Complete this concept map by choosing terms from the word bank and writing them in the correct spaces. Some terms may be used more than once.

atoms metals

bonds neutrons

compounds nonmetals

electrons periodic table

metalloids protons

Elements are composed of individual

are divided into 1.

5.

can join together to form 9. by forming chemical

made up of

and 2.

6.

10. and

and 3.

7. on the

between

11. and

4.

8.

Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once.

groups

left

periods

right

12. The horizontal rows of the periodic table are called

.

13. The vertical columns of the table are called

.

14. Except for the element hydrogen, all the elements on the side of the table are metals.

15. The elements

on the side of the table are nonmetals.

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Key Concept Builder

Electrons and Energy Levels Key Concept How is an electron’s energy related to its distance from the nucleus? Directions: On the line before each statement, write the letter of the correct answer.

1. Elements combine to form millions of A. metals. B. mixtures. C. compounds. 2. The forces that hold atoms together in combinations are called A. energy bonds. B. nuclear bonds. C. chemical bonds. 3. Every electron has a A. neutral charge. B. positive charge. C. negative charge. 4. The exact positions of the electrons in an atom cannot be determined because electrons are always A. moving. B. sharing. C. changing.

5. Compared with electrons that are closer to the nucleus, those that are farther away have A. less energy. B. more energy. C. equal energy.

6. The electrons that form bonds with other atoms are the A. midlevel electrons. B. innermost electrons. C. outermost electrons. 7. A neutral atom of an element has the same number of A. protons and neutrons. B. protons and electrons. C. neutrons and electrons.

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Key Concept Builder

Electrons and Energy Levels Key Concept Why do atoms gain, lose, or share electrons?

Directions: This diagram shows the first 18 elements of the periodic table. Use the diagram to answer each question on the lines provided.

1. How many valence electrons do atoms of hydrogen (H) have?

2. How many valence electrons do atoms of sulfur (S) have? 3. How many chemical bonds can an atom of carbon (C) form? Directions: Answer each question on the lines provided.

4. What is a valence electron?

5. What can valence electrons do?

6. What does the number of valence electrons that an atom has tell you about the atom?

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Key Concept Builder

Electrons and Energy Levels Key Concept Why do atoms gain, lose, or share electrons? Directions: Study the electron dot diagrams below. Circle the group-18 atoms. Then write the number of bonds each atom can form with other atoms on the line above each diagram.

1.

2.

hydrogen

3.

helium

4.

carbon

5.

nitrogen

neon

Directions: Answer each question on the lines provided.

6. Why are the atoms in group 18 stable?

7. What are the group-18 elements called?

8. What is the only way that an unstable atom can become stable?

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Enrichment

Triboluminescence English scholar Francis Bacon wrote in 1620: “It is well known that all sugar, whether candied or plain, if it be hard, will sparkle when broken or scraped in the dark.” Now, almost 400 years later, the underlying mechanism still isn’t fully understood, but the theory is that breaking the sugar crystals breaks their chemical bonds. Breaking the bonds separates opposite charges, and when the charges recombine, they release a burst of energy in the form of light. Triboluminescence is an optical phenomenon produced by relative motion between two contacting surfaces. Examples include wintergreen candies when chewed, and many adhesive tapes, which emit a flash of light when ripped from a surface.

Where the Light Comes From The energy level that an electron normally occupies is its ground state. When an electron occupies an energy shell greater than its ground state, it is in an excited state. An electron can become excited if it gets some extra energy, such as when it absorbs a photon or collides with a nearby atom or particle. When the electron returns from the excited state to its ground state, it emits a photon that has the amount of energy that the electron absorbed when it jumped to the excited state. Because there are many energy shells in any particular atom, there are many possible

energies that can be emitted as the electron drops to lower states. Because the energy and wavelength of a photon are related, emitted photons can be seen at a specific wavelength in the optical spectrum. In hydrogen, which is the least energetic element, an electron dropping down to the first level releases only enough energy to produce an ultraviolet photon. The more protons an element has, the more energy the electron levels can hold.

X-Rays In 1953, a team of scientists in Russia suggested that peeling sticky tape produced not only light, but X-rays. In 2008, researchers at the University of California decided to test transparent tape by peeling it in a vacuum. They determined that Xrays were given off in high-energy pulses, and that the intensity of the emission was strong enough to make peeling tape useful for X-ray photography. The researchers are not really sure why the tape is so heavily charged. They think that electrons leap from the roll to the adhesive side of the freshly yanked piece of tape, traveling so fast that they give off radiation, or energy, when they slam into it. The scientists calculate that this charge was ten times greater than typically seen in similar experiments and greater than the charge cited in current theories in the field.

Applying Critical-Thinking Skills Directions: Respond to each statement.

1. Consider whether the results of the experiment would have been the same if the researchers had not conducted it in a vacuum. Justify your decision.

2. Infer why scientists might have been relieved to realize that the X-rays were emitted only when the tape was peeled in a vacuum.

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Challenge

Looking for Answers The following materials have been reported to emit light or glow when they are peeled in the dark: • transparent tape • adhesive-bandage wrapper • athletic tape • fiberglass tape • duct tape • masking tape • hook-and-loop tape • sheets of paper connected with adhesive • wintergreen hard candy (crushed)

Design an Experiment Test three of the materials in the dark and record your observations about each one. Design an experiment that you could conduct to obtain more information about the triboluminescence phenomenon. Answer the following: • What information might you obtain from background research? • What question might you ask as a basis for the experiment? • How would you design the experiment? • Discuss the results of your pretest and design with a classmate or small group. Then refine each of your designs and discuss them with the class.

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Lesson Quiz A

Electrons and Energy Levels True or False Directions: On the line before each statement, write T if the statement is true or F if the statement is false.

1. The atomic number of an element equals the number of neutrons in an atom of that element.

2. The exact position of electrons of an atom cannot be determined. 3. The electrons closest to the nucleus of an atom have the least amount of energy.

4. The number of valence electrons in an atom tells you how many chemical bonds that atom can form.

Multiple Choice Directions: On the line before each question or statement, write the letter of the correct answer.

5. The number of bonds an atom can form is represented in an electron dot diagram by A. pairs of dots B. unpaired dots C. total number of dots

6. Which part of an atom participates in chemical bonding? A. proton B. neutron C. electron 7. An electron dot diagram shows A. the number of valence electrons. B. the strength of electron energy fields. C. the spacing arrangement of electrons. 8. Except for helium atoms, atoms tend to gain, lose, or share valence electrons until they have A. no B. four C. eight

valence electrons.

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Lesson Quiz B

Electrons and Energy Levels Completion Directions: On each line, write the term that correctly completes each sentence.

1. The

number of an element equals the number of protons

in an atom of that element.

2. The exact position of the electrons of an atom cannot be determined because they are in constant

3. The electrons

. to the nucleus of an atom have the least

amount of energy.

4. The number of

in an atom tells you how many chemical

bonds that atom can form.

Short Answer Directions: Respond to each statement on the lines provided.

5. Determine how an electron dot diagram provides information on the number of bonds an atom of a certain element can form.

6. Write an example of two types of atoms that are likely candidates to form a chemical bond.

7. Draw an electron dot diagram for fluorine (F), which has seven valence electrons.

8. Explain why some elements, such as the noble gases, are stable and do not react with other atoms, but the atoms of other elements are unstable and form chemical bonds easily....