Download Ch 11 HW

7th Physical Science HW15/ WS 15
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Ch 11 HW
Section 11.1 History & Intro. (Pg. 317)
3. The _____________________ is where most of an atom’s mass is located.
5. What did Dalton do in developing his theory that Democritus did not do?
7. What refinements did Bohr make to Rutherford’s proposed atomic theory?
8. Making Comparisons Compare the location of electrons in Bohr’s theory with the location of electrons in the
current atomic theory.
10. What about the atomic model shown below was shown to be incorrect?
Section 11.2 The Atom
Complete each of the following sentences by choosing the correct term from the word bank.
atomic mass unit
atomic number
mass number
atomic mass
2. An atom’s ______________________ is equal to the number of protons in its nucleus.
3. An atom’s ______________________ is equal to the weighted average of the masses of all the naturally
occurring isotopes of that element.
UNDERSTANDING KEY IDEAS
______ 4. Which of the following particles has no electric charge?
a. proton
b. neutron
c. electron
d. ion
5. Name and describe the four forces that are at work within the nucleus of an atom.
6. MATH SKILLS The metal thallium occurs naturally as 30% thallium-203 and 70% thallium-205. Calculate the
atomic mass of thallium. Show your work below.
8. Predicting Consequences Could a nucleus of more than one proton but no neutrons exist? Explain.
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7th Physical Science HW15/ WS 15
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Chapter Review (Pg. 328)
2. All atoms of the same element contain the same number of __________________
4. The _________________________ of an element is the number of protons and neutrons in the nucleus.
5. The __________________________ is an average of the masses of all naturally occurring isotopes of an element.
.7. How many protons does an atom with an atomic number of 23 and a mass number of 51 have?
______ 8. In Rutherford’s gold-foil experiment, Rutherford concluded that the atom is mostly empty space with a
small, massive, positively charged center because
a. most of the particles passed straight through the foil.
b. some particles were slightly deflected.
c. a few particles bounced straight back.
d. All of the above
______ 9. Which of the following determines the identity of an element?
a. atomic number
b. mass number
c. atomic mass
d. overall charge
14. Math Skills Calculate the number of protons, neutrons, and electrons in an atom of zirconium-90 that has no
overall charge and an atomic number of 40. Show your work below.
18. Analyzing Methods If scientists had tried to repeat Thomson’s experiment and found that they could not,
would Thomson’s conclusion still have been valid? Explain your answer.
INTERPRETING GRAPHICS
Use the diagrams below to answer the questions that follow.
19. Which diagrams represent isotopes
of the same element?
20. What is the atomic number for A?
21. What is the mass number for B?
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Vocabulary Activity
Atomic Anagrams
After you finish reading the chapter, try this puzzle.
Use the definitions below to unscramble the vocabulary words.
1. weighted average of the mass of all naturally occurring isotopes of the same element
MICTOA SAMS _______________________________________________________
2. the smallest unit of an element that maintains the properties of an element
MOATS______________________________________________________________
3. positively charged particle in the atom
TORPNO ____________________________________________________________
4. made up of protons and neutrons
UCSELUN ___________________________________________________________
5. particle in the atom that has no charge
TRONUNE___________________________________________________________
6. atoms with the same number of protons but different numbers of neutrons
SOOTPIES ___________________________________________________________
7. negatively charged particle in the atom
CLEENROT__________________________________________________________
8. number of protons in a nucleus
MICOTA BRUMEN____________________________________________________
9. regions where electrons are likely to be found
RENECTOL SCUDLO _________________________________________________
10. SI unit used to express the mass of atomic particles
TMCOAI SASM NTUI__________________________________________________
11. sum of protons and neutrons
SAMS BRUNEM ______________________________________________________
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Ch 11 Atoms Study Guide
Section 11.1
Some History on The Building Blocks of Matter
Q
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Who?
When
What
Atomic Model
__________________________________
Democritus
Why? This Greek philosopher wondered…
John Dalton
Why?
J.J. Thomson
Why? (See Pg. 314 Figure 3)
Ernest
Rutherford
Why? (See Pg. 315 Figure 5)
Erwin
Schrodinger/
Werner
Heisenberg
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Can you see an atom? ____________
To “see” something, we need ________________________________. The wavelength of light is ___________
Atoms are smaller than that.
Scanning tunneling electron microscope:
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7th Physical Science HW15/ WS 15
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How do we know about atoms without seeing them?
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The Basic Bohr Model (Pg. 316)
Atom
Relative size:
Nucleus
Relative size:
Size of nucleus ~ ________________size of atom
Dense: A nucleus the size of a grape weighs
_________________
Tiny __________________
Electron
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Electric Charge =
_____________electrons = mass of 1 proton
_____________ or ____________________.
___________________________________attract. ___________________________ repel.
Section 11.2
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Atom = ____________________________________________.
An atom is _________________ surrounding a _________________.
Exact composition of the nucleus is ____________________. Recently, scientists have found that protons
and neutrons are made of even smaller particles called _________________________.
These quarks have +2/3 charge: ____________, ________________, __________________.
These quarks have -1/3 charge: _______________, ________________, ________________.
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How small are atoms? Foil thickness ~ ______________ atoms thick.
How many different kinds of atoms are there? ________________________
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What is an atom made of?
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An atom has
Net Charge
Ion?
1 proton, 1 electron
6 protons, 3 electrons
2 protons, 3 electrons
Lost an electron
Gained an electron
# electrons = # protons
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Can you have a nucleus with 8 protons but no neutrons?
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e ≈ 1.602 × 10 −19 Coulombs
Atom Part
Electric
Charge
1 atomic mass unit ≈ 1.7 × 10 −21 kg
Mass
Special Words
Q The carbon-12 isotope has 6 protons, so every carbon isotope has ______________________________.
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Q Mass of an atom ≈ ______________________________
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Isotope Symbol
Isotope Name
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Drawing Isotopes
Hydrogen-1
Helium-4
Carbon-12
Oxygen-17
____protons
____protons
____protons
____protons
____neutrons
____neutrons
____neutrons
____neutrons
No charge
No charge
No charge
No charge
atomic number = _____
atomic number = _____ atomic number = _____
atomic number = _____
mass number = ______
mass number = ______
mass number = ______
mass number = ______
this atom’s mass ≈____
this atom’s mass ≈____
this atom’s mass ≈____
this atom’s mass ≈____
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Drawing Isotopes
Hydrogen-2
Helium-4
Carbon-14
Oxygen-16
____protons
____protons
____protons
____protons
____neutrons
____neutrons
____neutrons
____neutrons
No charge
No charge
No charge
No charge
atomic number = _____
atomic number = _____ atomic number = _____
atomic number = _____
mass number = ______
mass number = ______
mass number = ______
mass number = ______
this atom’s mass ≈____
this atom’s mass ≈____
this atom’s mass ≈____
this atom’s mass ≈____
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Relative Atomic Mass = _________________________________________________________________
(Pg. 323) Chlorine-35 makes up 76% of all the chlorine in nature, and chlorine-37 makes up the other 24%.
What is the atomic mass of chlorine?
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(Pg. 323) Silver occurs naturally as 52% silver-107 and 48% silver-109. What is the atomic mass of silver?
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(Pg. 323) Boron occurs naturally as 20% boron -10 and 80% boron-11. What is the atomic mass of boron?
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(Pg. 323) Silicon occurs naturally as 92% silicon -28, 5% silicon-29, and 3% silicon-30. What is the atomic
mass of silicon?
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Periodic Table (Pg. 338)
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Gold: Chemical symbol _______________
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How many neutrons are in uranium-238?
Number of protons = ______________.
Around how many neutrons are in gold atoms?
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Just some notes:
There are a little over _________ known elements.
There are around _____________ known isotopes.
_______ is the element with the most isotopes. It has ______ isotopes.
The least-stable isotope is ________________, which decays at a rate of ______________________.
The 4 Fundamental Forces of Physics
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Name
Description
Picture
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