Download atomic structure intro - Hood River County School District

Unit 3 Assignment Packet
Name:____________________________
Period:_________
A1: Atomic Structure Worksheet (Goals 1 – 3, Chapter 4)
1. Democritus, who lived in Greece during the 4th century B.C., suggested that
made up of tiny particles that cannot be divided. He called these particles
is
.
2. Explain why the ideas of Democritus were not useful in a scientific sense.
3. The modern process of discovery about atoms began with the theories of an English school teacher
named
.
4. Circle the letter of each sentence that is true about Dalton’s atomic theory.
a. All elements are composed of tiny, indivisible particles called atoms.
b. An element is composed of several types of atoms.
c. Atoms of different elements can physically mix together, or can chemically combine in simple
whole number ratios to form compounds.
d. Chemical reactions occur when atoms are separated, joined, or rearranged; however, atoms of
one element are never changed into atoms of another element when the atoms of elements A
and B combine chemically.
5. Which atomic particles carry a negative charge?
6. Thomson observed that the production of cathode rays did not depend on the kind of gas in the tube
or the type of metal used in the electrodes. What conclusion did he draw from these observations?
7. Explain Thomson’s Plum Pudding model of the atom (often called the cookie dough model).
8. How many units of positive charge remain if a hydrogen atom loses an electron?
9. The positively charged subatomic particle that remains when a hydrogen atom loses an electron is
called a(n)
.
10. Circle the letter of each sentence that is true about the nuclear theory of atoms suggested by
Rutherford’s experimental results.
a. An atom is mostly empty space.
b. All the positive charge of an atom is concentrated in a small central region called the nucleus.
c. The nucleus is composed of protons.
d. The nucleus is large compared with the atom as a whole.
e. Nearly all the mass of an atom is in its nucleus.
11. Describe Rutherford’s gold foil experiment and explain how his results improved upon Thomson’s Plum
Pudding model of the atom.
12. Fill out the following table:
Name
Symbol
Charge
Mass (amu)
electron
proton
neutron
13. Would you expect two electrons to attract or repel each other? Why?
14. What is the charge, positive or negative, of the nucleus of every atom?
15. Why is every atom electrically neutral?
A2: Isotopes Worksheet (Goal 4 – 5, Chapter 4)
1. Write the isotopic symbols for the isotopes of uranium having the following number of neutrons.
a.
142 neutrons
b.
143 neutrons
c.
146 neutrons
2. Fill in the following table:
Name
# of protons
Boron-10
SulfurIodine-127
-36
17
Calcium-
# of neutrons
# of electrons
17
20
3. What do isotopes of the same element have in common? How do isotopes of the same element
differ?
4. Fill in the following table:
Name
# of
electrons
# of
protons
# of
neutrons
6
6
3
70
4
atomic
number
carbon-
mass
number
14
tin-119
50
5. Write the isotopic symbols for argon-36, argon-38, and argon-40.
6. How can there be more than 1000 different atoms when there are only about 100 different elements?
7. How is the carbon-12 atom used to define atomic mass unit?
8. Distinguish among atomic mass and mass number.
9. What data must you know about the isotopes of an element to calculate the atomic mass of the
element?
10. Element X has two naturally occurring isotopes. The isotope with mass of 10.0 amu has a relative
abundance of 20.0%. The isotope with a mass of 11.0 amu has a relative abundance of 80.0%.
Calculate the value of the atomic mass of element X. State the atomic number and true identity of
element X.
11. The lithium found in a hearing aid battery has two naturally occurring isotopes. Lithium-6 has a mass
of 6.01 amu and an abundance of 7.42%. Lithium-7 has a mass of 7.01 amu and an abundance of
92.58%. Calculate the atomic mass of lithium.
12. Bohr Model Practice Problems
Directions: complete each of the following models using what you know about atoms. The first is
completed for you as an example.
Atomic # 7__
Atomic # ____
Atomic # ____
Atomic # ____
Atomic Mass 14__
Atomic Mass_12_
Atomic Mass_40_
Atomic Mass____
Element: Nitrogen
Element:_____________
Element:_____________
Symbol_ N_
Element:_____________
Symbol C_
Symbol_____
Symbol _H_
Atomic # ____
Atomic # ____
Atomic # ____
Atomic # ____
Atomic Mass_40_
Atomic Mass_11_
Atomic Mass_27_
Atomic Mass_32_
Element:_____________
Element:_____________
Element:_____________
Element:____________
Symbol_____
Symbol _B_
Symbol_____
Symbol_____
A3: Atomic Theory and Orbitals Worksheet (Goals 6-9, Chapter 5)
1. Describe how the quantum theory of atomic structure differs from Bohr’s theory.
( Hint: Focus on electrons)
2. Differentiate between an orbit and an orbital.
3. How are electrons in the ground state different from electrons in the excited state?
4. What unusual property is observed when an electron falls from excited state to a ground state?
5. How many orbitals are in the fourth energy level?
6. How many orbitals of each type are there?
s-
p-
d-
f-
7. Draw pictures of a single 2s and 2p orbital.
8. What is a line spectrum? What does it represent?
9. Fireworks give off many different colors. Using Bohr’s theory and your observations from the
spectroscope, explain how the firework’s chemicals produce different colors.
10. Why do we not see a line spectrum with our eyes from the fireworks?
Atomic Orbitals and the Periodic Table
1s
2s 2p
3s 3p
4s 4p
5s 5p
6s 6p
7s 7p
3d
4d
5d
6d
7d
4f
5f



Rule 1: Aufbau Principle: electrons enter orbitals of lowest energy first
Rule 2: Hund's Rule: when electrons occupy orbitals of equal energy, one electron enters each orbital
until all of the orbitals contain one electron with parallel spins
Rule 3: Pauli Exclusion Principle: an atomic orbital can describe at most two electrons
Directions: Write complete Electron Configurations and Orbital Diagrams for the following.
H
Be
C
Ne
Na
Cl
Fe
Hg
O2Ca2+
A4: Electron configs w/ Shorthand (goals 6-9, Chaper 5)

Rule 4: Noble Gas Shorthand Method: The last noble gas that was completed prior to arriving at
your element can be written down with the symbol of that noble gas in [brackets]. Then complete the
valence electrons to arrive at your element. We assume that the electrons are full in every shell up to
that noble gas.
Directions: Write complete Electron Configurations for the following empty boxes only.
Noble Gas
Element
Long Method
Shortcut Method
Br
1s22s22p63s23p64s23d104p5
[Ar] 4s23d104p5
Br-1
Mg
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
He
xxxxxxxxxxxxxx
Li
Element
B
Long Method
Noble Gas
Shortcut Method
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
H
xxxxxxxxxxxxxx
S
S-2
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Ti
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
As
Na
xxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
P
xxxxxxxxxxxxxx
Cr
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Co
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Ag
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Al
Al+3
Ne
xxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxx
A6: The Periodic Table: Organizing the Elements (Goals 10-12, Chapter 6)
A. periodic table
D. periods
G. columns
J. noble gases
M. metalloids
O. atomic number
B. metals
E. alkali metals
H. periodic law
K. group
N. inner transition metals
P. representative elements
C. nonmetals
F. halogens
I. alkaline earth metals
L. transition metals
Use this completion exercise to check your understanding of the concepts and terms associated with the
organization of the periodic table. Each blank can be completed with a term. Some terms may be used more
than once or not at all. Put the LETTER of the correct term in the space provided.
The periodic table organizes the elements into vertical _____ and horizontal _____ in order of
increasing _____. The table is constructed so that the elements having similar properties are in the same
_____. The elements in Groups 1A through 7A are called the _____. The _____ makeup Group 8A. The
elements in Groups 2A and 3A are interrupted in periods 4 and 5 by the _____ and in the periods 6 and 7 by
the _____. The group 1A elements are called the _____, and the group 2A elements are called the _____. The
nonmetals of group 7A are called the _____. Elements with properties that are intermediate between those
of metals and nonmetals are called _____.
Classify each statement as true or false.
_____ 1. In his periodic table, Mendeleev arranged elements in ascending order of atomic number.
_____ 2.
The representative elements are the Group A elements.
_____ 3.
The transition metals and inner transition metals are the Group B elements.
_____ 4.
The element in group 4A, period 3, is gallium
Match each description in Column B to the correct term in Column A.
Column A
Column B
a. A vertical column of elements in the
_____ 5. periodic table
periodic table
_____ 6. periods
b. The Group 8A elements
c. The Group 1A elements
_____ 7. group
d. A portion of the Group B elements
_____ 8. representative elements
e. An arrangement of elements according to
similarities in their properties
_____ 9. alkali metals
f. Group A elements
g. The horizontal rows of the periodic table
_____ 10. transition metals
h. The Group 7A element
_____ 11. halogens
_____ 12. noble gases
Answer the following questions in the space provided.
13. List the elements of Group 5A. Tell whether each is a metal, nonmetal, or metalloid.
14. List three properties of metals, nonmetals, and metalloids.
A7: Periodic Table and Trends (Goals 10-12, Chapter 6)
1. What determines the vertical arrangement of the periodic table?
2. What determines the horizontal order of the periodic table?
3. What determines the order of the periodic table?
4. Why did Mendeleev and other scientists of his time arrange elements in the periodic table in order of
atomic masses?
5. All halogens are highly reactive. What causes the similarity among the halogens?
6. What properties do Noble gasses share and how does this relate to their electron configuration?
7. For each element tell which period and group the element is in, identify the element, and state
whether it is a metal, nonmetal, or metalloid.
Element
#34
#40
#14
#56
#18
Period
Group
Identity
Metal, non, metalloid
8. Classify the following as metals, nonmetals or metalloids below each name:
manganese
. arsenic
carbon
niobium
radium
9. Iodine is used in many commercial chemicals and dyes. To what family does it belong? What
are the other members of this family? How many electrons are in the outermost energy level?
10. Define atomic size and describe its trend on the periodic table.
11. Define ionization energy and describe its trend on the periodic table.
12. Define electronegativity and describe its trend on the periodic table.
13. Explain why as you go down the periodic table, within a group, the atoms get larger.
14. Explain why as you go across the periodic table to the right, within a period, the atoms get
smaller.
15. As an atom gets smaller the ionization energy becomes greater. Using atomic structure, explain
this statement.
16. Explain how electronegativity is related to atomic size using the trends on the periodic table.