Download File - Unit #1-0

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Element Symbols:
An element’s symbol can stand for one atom of the element or one mole of atoms of
the element. (One mole = 6.02 x 1023 atoms of an element.)
Write the symbol for the following elements.
1.
oxygen
11. plutonium
2.
hydrogen
12. americium
3.
chlorine
13. radium
4.
mercury
14. germanium
5.
fluorine
15. zinc
6.
barium
16. arsenic
7.
helium
17. lead
8.
uranium
18. iron
9.
radon
19. calcium
10. sulfur
20. cobalt
Write the name of the element that corresponds to each of the following symbols.
21. Kr
31. Cu
22. K
32. Ag
23. C.
33. P
24. Ne
34. Mn
25. Si
35. I
26. Zr.
36. Au
27. Sn
37. Mg
28. Pt
38. Ni
29. Na
39. Br
30. Al
40. Hg
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Atomic Structure: Quiz #3
An atom is made up of protons and neutrons (both found in the nucleus) and
electrons (in the surrounding electron cloud). The atomic number is equal to the
number of protons. The mass number is equal to the number of protons plus
neutrons. In a neutral atom, the number of protons equals the number of electrons.
The charge on an ion indicates an imbalance between protons and electrons. Too
many electrons produces a negative charge, too few, a positive charge.
This structure can be written as part of a chemical symbol.
Example:
7 protons
8 neutrons (15 - 7)
15 +3
mass number N charge
4 electrons remaining (7-3)
atomic number7
Complete the following chart.
Element/
Ion
1. H
2.
Atomic
Number
Atomic Mass
Mass
Number
Protons
Neutrons
Electrons
H+
3 12 6C
4.
73Li+
5. 35 17CI6.
39K
19
7. 2412Mg2+
8. As39.
Ag
10. Ag+1
11.
S-2
12.
U
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Isotopes and Average Atomic Mass:
Elements come in a variety of isotopes, meaning they are made up of atoms
with the same atomic number but different atomic masses. These atoms
differ in the number of neutrons. The average atomic mass is the weighted
average of all the isotopes of an element.
Example:
A sample of cesium is 75%
average atomic mass?
133
Cs, 20%
132
Cs and 5%
134
Cs. What is its
Answer:
.75 x 133 = 99.75
.20 x 132 = 26.4
.05 = 134 = 6.7
Total =
132.85 amu = average atomic mass
Determine the average atomic mass of the following mixtures of isotopes.
1. 80% 1271, 17% 1261, 3% 1281
2. 50% 197 Au, 50% 198Au
3. 15% 55Fe, 85% 56Fe
4. 99% lH, 0.8% 2H, 0.2% 3H
5. 95% 14N, 3% 15N, 2% 16N
6. 98% 12C, 2% 14C
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Electron Configuration:
Electrons are distributed in the electron cloud into principal energy levels (l, 2,
3), sublevels (s, p, d, f), orbitals (s has 1, P has 3, d has 5, f has 7) and spin (two
electrons allowed per orbital).
Example: Draw the electron configuration of sodium (atomic # 11).
Answer:
1s2
2s22p6
3s1
Draw the electron configurations of the following atoms.
1. Cl
2. N
3. Al
4. 0
5. P
6. K
7. Ti
8. Ar
9. Zn
10. Si
11. C
12. F
13. I
14. Sr
15. Mn
16. Mg
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Valence Electrons:
The valence electrons are the electrons in the outermost principal energy level. They
are always "s" or "s and p" electrons. Since the total number of electrons possible in s
and p sublevels is eight, there can be no more than eight valence electrons.
Determine the number of valence electrons in the atoms below.
Example: Carbon
Electron configuration is 1s
2
2s2 2p2. Carbon has 4 valence electrons.
1. fluorine
11. lithium
2. phosphorus
12. zinc
3. calcium
13. carbon
4. nitrogen
14. iodine
5. iron
15. oxygen
6. argon
16. barium
7. potassium
17. aluminum
8. helium
18. hydrogen
9. magnesium
19. xenon
10. sulfur
20. copper
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Periodic Table Worksheet:
1. Where are the most active metals located?
2. Where are the most active nonmetals located?
3. As you go from left to right across a period, the atomic size (decreases
increases). Why?
/
4. As you travel down a group, the atomic size (decreases / increases). Why?
5. A negative ion is (larger / smaller) than its parent atom. 6. A positive ion is (larger /
smaller) than its parent atom.
7. As you go from left to right across a period, the first ionization energy generally
(decreases / increases). Why?
8. As you go down a group, the first ionization energy generally (decreases /
increases). Why?
9. Where is the highest electronegativity found?
10. Where is the lowest electronegativity found?
11. Elements of Group 1 are called
12. Elements of Group 2 are called
13. Elements of Group 3-12 are called
14. As you go from left to right across the periodic table, the elements go from (metals
/ nonmetals) to
( metals / nonmetals).
15. Group 17 elements are called
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16. The most active element in Group 17 is
17. Group 18 elements are called
18. What sublevels are filling across the Transition Elements?
19. Elements within a group have a similar number of
20. Elements across a series have the same number of
21. A colored ion generally indicates a
22. As you go down a group, the elements generally become ( more / less) metallic.
23. The majority of elements in the periodic table are (metals / nonmetals).
24. Elements in the periodic table are arranged according to their
25. An element with both metallic and nonmetallic properties is called a
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Ionic Bonding:
Ionic bonding occurs when a metal transfers one or more electrons to a nonmetal in an
effort to attain a stable octet of electrons. For example, the transfer of an electron from
sodium to chlorine can be depicted by a Lewis dot diagram.
Na' + .CI:
-- Na+CI
Calcium would need two chlorine atoms to get rid of its two valence electrons.
CI' +
a + .CI:
Ca+2CI2
Show the transfer of electrons in the following combinations.
1. K + F
2. Mg + I
3. Be + S
4. Na + 0
5. AI + Br
Covalent Bonding:
Covalent bonding occurs when two or more nonmetals share electrons, attempting to
attain a stable octet of electrons at least part of the time.
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For example:
H. + xCI_
_CI _
J'-
xx
Note that hydrogen is content with 2,
not 8, electrons.
Show how covalent bonding occurs in each of the following pairs of atoms. Atoms
may share one, two or three pairs of electrons.
1 . H + H (H2)
2. F + F (F)
3. o + o (°2)
4. N + N (N2)
5. C + o
(CO)
6. H + o (H2O)
Balancing Chemical Equations:
Rewrite and balance the equations below.
1. N2 + H2 --,-. NH3
2. KCI03 --,-. KCI + 2
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3. NaCI + F2 --,-. NaF + CI2
4. H2 + 2 --,-. H2O
5. AgN03 + MgCI2 --,-. AgCI + Mg(N03)2
6. AIBr 3 + K2SO 4 --,-. KBr + AI2(SO 4)3
7. CH4 + 2 --,-. CO2 + H2O
I8.
C3Ha + 2 --,-. CO2 + H2O
9. CaH,a + 2 --,-. 1 2
+ H2O
10. FeCI3 + NaOH --,-. Fe(OH)3 + NaCI
11. P + 2 --,-. P2OS
12. Na + H2O --,-. NaOH + H2
13. Ag2O --,-. Ag + 2
14. Sa + 2 --,-. S03
15. CO2 + HP --,-. C6H1206 + 2
16. K+MgBr2 --,-. KBr+Mg
17.
HCI
+
CaC03
--,-.
CaCI2
+
H2O
+
CO2
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Word Equations:
Write the word equations below as chemical equations and balance.
1. zinc + lead (II) nitrate yield zinc nitrate + lead
2. aluminum bromide + chlorine yield
aluminum chloride + bromine
3. sodium phosphate + calcium chloride yield
chloride
calcium
4. potassium chlorate when heated yields potassium
5. aluminum + hydrochloric acid yield
phosphate
+
sodium
chloride + oxygen gas
aluminum chloride + hydrogen gas
6. calcium hydroxide + phosphoric acid yield
calcium phosphate + water
7. copper + sulfuric acid yield copper (II) sulfate + water +
sulfur dioxide
8. hydrogen + nitrogen monoxide yield water + nitrogen
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Classification of Chemical Reactions:
Classify the reactions below as synthesis, decomposition, single replacement (cationic
or anionic) or double replacement.
1. 2H2 + °2 _ 2H20
2. 2H20 _ 2H2 + °2
3. Zn + H2SO4 _ ZnS04 + H2
4. 2CO + °2 _ 2CO2
5. 2HgO _ 2Hg + °2
6. 2KBr + CI2 _ 2KCI + Br2
7. CaO + H2O _ Ca(OH)2
8. AgN03 + NaCI _ AgCI + NaN03
9. 2H202 _ 2H20 + °2
10. Ca(OH)2 + H2SO4 _. CaSO4 + 2H20
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Predicting Products of Chemical Reactions:
Predict the products of the reactions below. Then, write the balanced equation and
classify the reaction.
1. magnesium bromide + chlorine
2. aluminum + iron (III) oxide
_
II II
3. silver nitrate + zinc chloride
4. hydrogen peroxide (catalyzed by manganese dioxide)
5. zinc + hydrochloric acid
6. sulfuric acid + sodium hydroxide
1_7. sodium + hydrogen
8. acetic acid + copper
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