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Name ____________________________________
Study Guide for Chemistry I Semester One Final Exam
Chapt.
1
2
3
Topics
Book Objectives:
What is chemistry
Know the steps in the scientific method
Book Objectives:
Know the differences between solids, liquids and gases
Know the differences between elements, compounds and mixtures
Be able to tell the difference between chemical and physical changes (definition, examples)
Know what different separation techniques can separate (elements/compound/mix)
Know the law of conservation of matter
EOC Targets:
C-Matter-101. I can define what matter is.
C-Matter-102. I can differentiate between a solid, liquid, and gas.
C-Matter-103. I can explain that matter cannot be created or destroyed in a chemical
reaction or physical change.
C-Matter-104 I can classify matter as an element, compound, or mixture.
C-Matter-201. I can explain what physical and chemical properties are, and list examples.
C-Matter-202. I can describe how density relates to mass and volume for matter.
C-Matter-203. I can calculate density given the mass and volume, or calculate relationships
between density, mass and volume
C-Matter-204. I can differentiate between mass and density.
C-Matter-301. I can explain what happens to matter during a physical or chemical change.
Book Objectives:
Be able to determine the correct sigs figs / calculations (+-x÷)
Know the metric prefixes – sizes
Be able to convert between °C and K
Be able to calculate density
Be able to convert metric units
Be able to set up factor label problems
Be able to convert between scientific notation and decimal notation
Know what different units measure
Know the difference between accuracy and precision
Know the difference between quality and quantity
Book
Examples
Pg.51 (18-19)
Pg. 58 (45, 47,
49, 69)
Pg. 70 (5, 6, 7,
8)
Pg. 78 (16, 17)
Pg. 84 (33, 34)
Pg. 91 (46, 47)
EOC Targets:
C-Measurement-1501. I can recognize the uncertainty of measurements.
C-Measurement-1502. I can choose and use appropriate lab equipment to measure
properly.
C-Measurement-1503. I can choose appropriate SI units and convert between them.
C-Measurement-1504. I can use scientific notation and interpret the meaning of the power
of ten. (For example, knowing that 10-6 is smaller than 10-2)
4
Book Objectives:
Know the subatomic particles (relative sizes and charges, location)
Be able to calculate the average atomic mass from isotope masses
Pg. 112 (1718)
1
Be able to write atomic symbols and determine number of p, n, e, mass number, or atomic
number
Know the major scientists, their experiments and discoveries
Know early models of the atom
Know what isotopes are and how they are different
Know periods and families
5
6
7
EOC Targets:
C-Atomic Structure -1801. I can identify the location, charge, and relative mass of each
subatomic particle: (electron, neutron, and proton).
C-Atomic Structure -1802. I can recognize that electrons exist in energy levels outside the
nucleus.
C-Atomic Structure -1803. I can identify the element based on the number of protons.
C-Atomic Structure -1902. I can explain how the number of protons and electrons relates to
the charge of the atom or ion.
C-Atomic Structure -2001. I can explain how the number of protons and neutrons relates to
the mass number.
C-Atomic Structure -2002. I can define isotope by explaining that atoms of an element can
contain different numbers of neutrons.
Book Objectives:
Know Bohr’s model and how electrons behave, excite/ground state, atomic spectra
Know quantum model: orbitals, sublevels, energy levels, # electrons
Know the EMR spectrum, relative energy, wavelength and frequency
Know relationship between energy, wavelength and frequency
Be able to write electron configurations (ions and neutral atoms)
Know rules for writing orbital diagrams (AUFBAU, Hund, Pauli)
Be able to identify excited electron configurations/orbital diagrams
Know parts of a wave: amplitude, wavelength and frequency
Book Objectives:
Know the trends on the periodic table (type ion, ion size, electronegativity, metal/NM(
(highest vs lowest)
Know s, p, d, f blocks
Kow ion radius changes
Know family names and locations on Periodic Table
Know how Medeleev organized the periodic table and the periodic law
Know location of metals, nonmetals and metalloids
EOC Target:
C- Periodic Table-2301. I can differentiate between groups and periods on the periodic table
and what is common about elements within a group.
C- Periodic Table-2302. I can locate metals, non-metals and metalloids on the periodic table.
C- Periodic Table-2303. I can list properties of metals, non metals and metalloids.
C- Periodic Table-2305. I can determine the charge of a main block (representative) ion.
C- Periodic Table-2306. I can determine the number of valence electrons for a main block
(representative) element.
Book Objectives:
Be able to write electron configurations of ions
Be able to identify formulas as ionic or metallic
Be able to draw electron dot diagrams of ions
Pg. 115 (2324)
Pg. 122 (43)
Pg. 135 (8)
Pg. 167 (8-9)
Pg. 181 (39,
43)
Pg. 207 (41,
63, 67, 79)
2
know what valence electrons are and how many an atom has
Know how ions form and why
Know structure and behavior of ionic and metallic bonds
9
EOC Targets:
C-Atomic Structure -1901. I can explain how ions are formed and predict their charge.
C-Bonding- 2101. I can identify a compound as ionic from the types of elements in the
compound.
C-Bonding- 2102. I can explain an ionic bond using electrostatic attraction.
C-Bonding- 2103. I can describe the general characteristics of an ionic compound (solubility,
melting point, alternating ions create a simple crystalline structure, electrical conductivity).
Book Objectives:
Be able to determine if elements will form ionic compounds
Be able to write names/formulas of ionic compounds (transition metal,8 polyatomic ions)
Know charges of ions by family location
Pg. 264 (13)
Pg. 281 (43,
57, 61, 65, 67,
69)
EOC Targets:
C-Nomenclatrue-401. I can use naming rules to name or write the formula for ionic
compounds.
25
Misc
Book Objectives:
Recognize that an unstable nucleus loses energy by emitting radiation during the decay
process.
Know how to write the symbols for an alpha particle, a beta particle, and a gamma ray.
Know the relative penetration ability of each form of radiation listed above.
Know what can be used to shield yourself from each form of radiation.
Be able to identify the missing particle in a transmutation equation.
Know the difference between fission and fusion.
Know the nuclear process that fuels our sun.
Page 800
Read table
25.1
Section review
25.2.
Section review
25.3
Know lab safety rules and
Know lab equipment and how to read them
Be able to interpret graphs
3
Name _______ANSWER KEY_________________ Period _______________ Date__________________
1. Which of the following is/are qualitative observation(s)?
The metal is shiny. The Al has a mass of 7.0g. The density of Al is 2.70g/cm3. The metal is ductile.
Which of the following is/are quantitative observation(s)?
The metal is shiny. The Al has a mass of 7.0g. The density of Al is 2.70g/cm3. The metal is ductile.
2. Read the graduated cylinder below: 6.60 mL
3. If a graduated cylinder has markings for the 10’s, and 1’s, how many decimal places will be in your measurement?
10’s – measure to the ones place.
1’s – measure to the tenths place
4. What pieces of laboratory equipment can be used to accurately measure the volume of a liquid?
Graduated cylinder
5. Which of the following are units for volume? mm, mL, m, cm, cm3, g/cm3, g, kg, L
6. Which of the following are units for mass? mm, mL, m, cm, cm3, g/cm3, g, kg, L
7. What is the relationship between 1mL and 1cm3? 1mL = 1cm3
8. What is the difference between precision and accuracy?
Accuracy – how close a measurement is to the true value
Precision – how consistent a set of measurements are
9. Which set of data points show the greatest precision? Each student massed an object three times.
Student one: 2.1 g 2.2 g 1.9g – Most precise because the measurements are in a very narrow range. In
other words, they are consistent.
Student two: 1.6 g 2.9 g 2.0g
Student three: 2.5g
3.0g
3.1g
10. Define matter.
Matter is anything that has mass and takes up space.
11. A student calculates the density of an object to be 3.00g/cm3. The true value is 2.50g/cm3. Calculate this
student’s percent error.
|2.50 – 3.00|/2.50 x 100% = 20%
12. The density of pure water is 1g/cm3. Which of the following items will float in water? A cork with a density of
0.87g/cm3, a rock with a density of 8.9g/cm3, oil with a density of 0.87g/cm3
13. Which state of matter is compressible? Compressible means you can squish it into a smaller space.Gas
14. Draw the particles in a solid, liquid, and gas.
15. Classify the following as an element, compound or mixture.
a. NaBr __Compound_______________
b. Br2
__Element_______________
c. Na + Br2__Mixture_______________
4
16. What is the difference between a mixture and a compound?
A compound is two or more elements that are bonded together. A mixture is two or more substances that are in a
container together but are not chemically connected.
17. What type of process is used to separate a mixture?(Is it chemical or physical?) Physical
18. What type of process is used to separate a compound?(Is it chemical or physical?) Chemical
19. What do the following symbols mean?
a. (s)
__Solid_______________
b. (l)
__Liquid_______________
c. (g)
__Gases_______________
d. (aq)
__Aqueous_______________
e. 
__Yields_______________
20. How can you separate a mixture of salt water?
Boil the salt water so that the water turns to gas. Salt will be left behind in the beaker.
21. How do you identify a substance as a compound?
Each substance has a unique set of properties by which it can be identified. For example, the color, melting point
temperature, density, odor, and reactivity can serve as clues for identifying the substance.
22. List four examples chemical change. What happens to matter during this change?
Color change, formation of a gas, formation of a precipitate, and energy change (light or heat) are all signs that a
chemical change has occurred. Bonds are broken, atoms are rearranged, and new bonds form during chemical changes.
23. List four examples a physical change. What happens to matter during this change?
Tearing a piece of paper, melting a stick of butter, dissolving salt in water, and crushing a peanut are all examples of
physical changes. The material is altered but the chemical composition is unchanged during a physical change.
24. Would cooking be considered a chemical or physical change? Explain.
Cooking is a chemical change because the properties of the food are changed. For example, meat changes color from
red to brown. The taste and odor of foods change when the food is cooked. These indicate that the chemistry of the
food is altered.
25. What evidence suggests a chemical change has occurred?
Color change, formation of a gas, formation of a precipitate, and energy change (light or heat) are all signs that a
chemical change has occurred.
26. Define the law of conservation of mass. Make drawing to represent this concept.
Matter cannot be created or destroyed.
OO + ∆Ω∆  OΩO + ∆∆
27. 2H2 + O2  2H2O
Label the reactants.
Label the products.
If you have 4 grams of hydrogen and 32 grams of oxygen, how many grams
of water would you make?
Reactants - H2 and O2
Products - H2O
You would make 36 grams of water.
28. What is the rule for multiplying/dividing numbers using significant figures?
Among the numbers that are multiplied or divided, the number with the fewest significant figures determines
the number of significant figures that the answer may have.
29. What is the adding rule for significant figures?
Among the numbers that are added or divided, the number that is the least detailed (stops at the earliest
placeholder) limits how detailed the answer may be. For example, when adding 10.1 and 5.000005, 10.1 is the
least detailed. It stops at the tenths spot. Therefore, the answer may only go to the tenths spot. 15.1
30. The following length measurements were taken by students using several different measuring devices. Find the
average of the measurements. Make sure that your answer has the correct number of significant figures.
10.05 cm, 10.1 cm, 9.741 cm, 10.6 cm, 10.5 cm
(10.05 + 10.1 + 9.741 + 10.6 + 10.5) / 5 = 51.0 / 5 = 10.2
5
31. Convert 30.0mg to g
30.0 mg x (1 g / 1000 mg) = 0.030 g
Convert 50.0kL to mL. 50.0 kL x (1000 L / 1 kL ) x ( 1000 mL / 1 L ) = 5.00 x 107 mL
Convert 3.5kg to mg
3.5 kg x (1000 g / 1 kg ) x ( 1000 mg / 1 g ) = 3.5 x 106 mg
32. Convert – 35 ˚C to K.
TK = T ˚C + 273
TK = -35 + 273
TK = 238 K
33. How many sig figs are in these numbers?
a. 34.0
___3_________
b. 0.0023
___2_________
c. 4500
___2_________
d. 100.00
___5_________
23
e. 6.023 x 10
___4_________
34. Place the number 0.0000000067 into scientific notation. 6.7 x 10-9
35. Place the following numbers on the number line below: 1x1010, -1, 1x101, 100, 1x10-10, 10
1x10-10
36.
37.
38.
39.
40.
41.
42.
43.
44.
-1
100
1x101
1x1010
10
0
Use factor label or dimensional analysis to convert 45.0 feet into cm. (12 inches = 1 ft ; 2.54cm = 1 inch)
45.0 feet x (12 inches / 1 ft) x (2.54 cm / 1 inch) = 1370 cm
In the measurement, 23.0 g, what is the estimated digit? The zero is the estimated digit.
Calculate the mass of an object with a density of 2.70g/cm3 and a volume of 45.2cm3.
Density = mass / volume
2.70 = mass / 45.2
(45.2)(2.70) = mass
122 g = mass
The density of osmium, which is the densest metal, is 22.57 g/cm3. Is a 230g block of metal that measures 1.00
cm 4.00 cm 2.50 cm osmium? Explain.
Volume = length x width x height = 1.00 cm 4.00 cm 2.50 cm = 10.0 cm3
230g / 10.0 cm3 =23 g/cm3
The sample is likely to be Osmium. Significant figures limit the precision of the answer so we cannot be sure.
Calculate the percent error for all the data recorded by the student of a glass rod labeled 23.490 cm. A student
measures the length of a glass rod five times and records the data as:
23.487 cm
Average = 23.495 cm
% error = 100% x (accepted – experimental) / accepted
23.493 cm
23.516 cm
% error = 100% x (23.490cm – 23.495cm)/(23.490cm)
23.501 cm
23.477 cm
% error = 0.02 %
Does any change violate the Law of Conservation of Mass?
Matter cannot be created or destroyed. Matter can be converted into energy according to Einstein’s famous
equation (E=mc2).
A 13-g sample of calcium reacts with bromine to form 24 g of calcium bromide. How many grams of bromine are
used in the reaction? 11 grams
What is the “Gold Foil Experiment”? What did this suggest about the structure of the atom?
Rutherford shot alpha particles at a sheet of gold foil. Most of the particles when straight through the foil while
a few were deflected. This suggests that the atom is mostly empty space in addition to having a small central
core that is positively charged.
List the number of protons, neutrons, and electrons in C.
6 protons, 7 neutrons, and 6 electrons
6
45. Where in the atom do you find all of the subatomic particles? It might be helpful to draw an atom.
Protons and neutrons are found in the center of the atom, called the nucleus. The electrons move about in the
electron cloud that surrounds the nucleus.
46. Which subatomic particle(s) defines the identity of the atom? Protons
47. Which subatomic particle(s) determines chemical properties? electrons
48. Which subatomic particle(s) have a relative mass of 1 amu? 0amu?
Protons and neutrons have a mass of 1 amu. Electrons have a mass of 0 amu.
49. Which subatomic particle(s) have a charge?
Protons are positively charged. Electrons are negatively charged.
50. What element has the atomic mass of 24 and an atomic number of 11? Sodium
51. What is the difference between an atom and an ion?
An atom is neutral. It has equal numbers of protons and electrons. An atom becomes an ion when it gains or
loses electrons.
52. What is the charge of an element with 12 protons and 10 electrons? +2
53. What is the difference between an atomic number and a mass number?
Atomic number is the number of protons in an atom. The mass number of an atom is the number of protons
and neutrons.
54. Consider an element Z that has two naturally occurring isotopes with the following percent abundances: the
isotope with a mass number of 19.0 is 55.0% abundant; the isotope with a mass number of 21.0 is 45.0%
abundant. Calculate the average atomic mass for element Z?
[ (19.0)(55.0) + (21.0)(45.0) ] / 100 = 19.9
55. Draw a model of the atom as described by Dalton, Thomson, and Rutherford.
Dalton
Thomson
Rutherford
electrons
56. In what block would you find the following elements?
K ___s___ Ba ___s_____ Cl ____p____ Sn___p___ Cu___d____ U____f___
57. Consider the following:
Ca -40
Ca-41
a. How many protons do these isotopes have?
______20_____
_____20______
b. How many neutrons do these isotopes have? ______20_____
_____21______
c. How many electrons do these isotopes have? ______20_____
_____20______
58. What is the definition of an isotope? How could you predict the most common isotope of an element?
Isotopes are atoms that have the same number of protons but different numbers of neutrons. The most
common isotope of an element has a mass number nearest to the average atomic mass of the element.
59. Where are the most active nonmetals located on the periodic table? Most active metals?
The mose active nonmetals are located up and to the right on the periodic table. These nonmetals have high
electronegativities, which means that they have a strong tendency to attract electrons. The most active metals
are found down and to the left on the periodic table. These elements have low ionization energies, which
means that little energy is required to remove an electron from these elements during a reaction.
60. In Bohr’s model, where are the electrons located?
Electrons are located on rings that surround the nucleus. The rings represent different energy levels.
61. What is the difference between the ground state and an excited state in reference to electron configuration?
When atoms are in the ground state, electrons fill orbitals of lowest energy first. In other words, they abide by
Aufbau’s Principle. The electron configurations of atoms in the ground state follow the typical filling order that
is laid out on the periodic table. When electrons are excited, they fill orbitals of higher energy regardless of
7
vacancies on lower energy levels. The electron configurations deviate from the typical filling order that is laid
out on the periodic table.
62. Which type of electromagnetic radiation has the highest frequency?
Gamma rays
63. Which color of visible light has the longest wavelength? The shortest?
Longest wavelength – Red
Shortest Wavelength – Violet
64. Why do metals emit photons when heated?
The heat energy is absorbed by electrons in the metallic atoms. The electrons become excited to a higher
energy level. They then fall back down to the ground state and emit the energy that they had absorbed.
65. The quantum mechanical model is based on mathematical _probabilities___.
66. How many orbitals are in an
a. s sublevel?
__1_____
b. p sublevel?
__3________
c. d sublevel?
___5________
d. f sublevel?
___7________
67. What is the maximum amount of electrons that can occupy an orbital? Two
68. Pauli’s exclusion Principle states that no more than two electrons can occupy an orbital, provided they have
opposite spins. In what directions can these electrons spin?
Up spin and down spin…or….+1/2 spin and -1/2 spin
69. What is the maximum number of electrons in the first energy level? The second energy level?
First energy level – 2 electrons
Second energy level – 8 electrons
70. Give the electron configuration for a neutral atom and an ion for each element below.
Element
Argon
Electron Configuration of Atom
1s22s22p63s23p6
Electron Configuration of Ion
1s22s22p63s23p6
Chlorine
1s22s22p63s23p5
1s22s22p63s23p6
Beryllium
1s22s2
1s2
Potassium
1s22s22p63s23p64s1
1s22s22p63s23p6
1s22s22p3
1s22s22p6
Nitrogen
71. What are valence electrons? How do you determine the valence electrons for a given atom?
The electrons in the outermost energy level, you can determine the valence electrons for groups IA-VIIIA by looking
at the periodic table.
72. Complete the following table.
Element
Atomic
Orbital Diagram
Electron Configuration
Number
Magnesium
12
1s22s22p63s2
1s
Nitrogen
Neon
2s
2p
3s
1s22s22p3
7
1s
2s
2p
1s
2s
2p
10
1s22s22p6
73. Explain why the 4s sublevel fills before the 3d sublevel begins to fill as electrons are added.
Electrons fill the sublevel with the lowest energy first. The 4s is lower in energy than the 3d.
74. How many periods are on the periodic table? 7
How many groups? 18
8
75.
76.
77.
78.
79.
80.
Where are the nonmetals located on the periodic table? Upper Right
Where would you find the transition elements? D-block….Middle of the periodic table. Group B elements.
What is the name of the group on the periodic table that is considered to be inert? Noble Gases
What are the properties of metals? Good conductors, high luster, ductile, malleable
What are the properties of nonmetals? Poor conductors, brittle, dull
What is the first element in each family?
a. Alkali metals
________lithium____________
b. Alkaline Earth metals ________beryllium____________
c. Halogens
________fluorine____________
d. Noble Gases
________helium____________
81. How many valence electrons do elements in each family have?
a. Alkali metals
______1______________
b. Alkaline Earth metals _______2_____________
c. Halogens
_______7_____________
d. Noble Gases
_______8_____________
82. Draw the electron dot structure (Lewis Structure) for the Halogen in the third period.
83. Draw the electron dot structure (Lewis Structure) for the Alkali metal in the fifth period
84. Draw the electron dot structure (Lewis Structure) for the Nobel gas in the fourth period.
85. What do elements in the same group have in common?
Same number of valence electrons, they will also have similar properties.
86. When elements in the following families form ions, what is the ion charge?
a. Alkali metals
___ +1 _________________
b. Alkaline Earth metals ___+2 _________________
c. Halogens
___-1_________________
d. Noble Gases
____neutral (no charge)_______________
87. As you move across the periodic table from left to right, what happens to the following properties?
a. atomic number
__increases__________________
b. atomic radius
__decreases__________________
c. ionization energy
__increases__________________
d. electronegativity
__increases__________________
88. As you down a group, what happens to the following properties?
a. atomic number
___increases_________________
b. atomic radius
___increases_________________
c. ionization energy
___decreases_________________
d. electronegativity
___decreases_________________
89. Which is larger, an ion of potassium or an atom of potassium? K+ the atom is larger than the cation.
90. Which is larger, an ion of oxygen or an atom of oxygen? The oxygen ion is larger, anions are larger than their
atom.
91. Arrange the elements given below in the increasing order of their atomic size. (smallest) A, D, B, C (largest)
Element A: 1s22s22p6
Element B: 1s22s2
Element C: 1s22s22p63s1
Element D: 1s22s22p3
92. What is the charge of an aluminum ion? A chloride ion? A nitride ion? A phosphide ion? A magnesium ion?
Al+3
Cl-1
N-3
P-3
Mg+2
9
93. What are the properties of ionic compounds? Use the following terms in your answer: electronegativity, melting
point, conducting electricity, crystalline structure, and solubility.
Ionic Compounds
Electronegativity
0.4 – 2.0
Melting points
high
Physical state
Solid (crystalline)
Electrical Conductivity
High when dissolved or melted
No conductivity as a solid
Solubility
Usually high in water
94. What are elements trying to achieve when forming compounds?
Noble gas configuration (octet rule) – eight valence electrons
95. What is a cation? How do atoms become cations?
Positively charged ion, they are formed by a neutral atom losing electrons.
96. What is an anion? How do atoms become anions?
Negatively charged ion, they are formed by a neutral atom gaining electrons.
97. Which of the following can form ionic compounds? (Choose all that apply)
a. Two cations
b. Two anions
c. A cation and an anion
d. Two nonmetals
e. Two metals
f. A metal and a nonmetal
98. What happens to electrons in an ionic compound?
Electrons are gained or lost . Metals (cations) lose their electrons, while nonmetals (anions) gain those electrons.
99. What is the formula for each compound below?
a. magnesium hydroxide?
Mg(OH)2
b. strontium nitrate?
Sr(NO3)2
c. ammonium sulfide?
(NH4)2S
d. potassium phosphate?
K3PO4
e. magnesium chloride?
MgCl2
100. Name the following compounds. Hint: Use the Stock system.
a. CuCl
Copper (I) chloride
b. SnCl2
Tin (II) chloride
c. FeBr3
Iron (III) bromide
d. SnO
Tin (II) oxide
101.
What is a metallic bond?
Metallic bonds join metal cations together. The metal atoms become cations by donating electrons to
the “sea of electrons” that surround the metal cations. The electrons in the “sea of electrons” are
delocalized (spread out) around the metal cations.
102.
Why are metals good conductors of electricity?
The electrons in the “sea of electrons” are free to flow through the metal forming an electric current.
103.
What piece of equipment do you use to move a hot beaker?
Beaker tongs
104.
What piece of equipment do you use to move a hot crucible?
Crucible tongs
105.
What should be the last thing you do before leaving the lab table?(Think safety!)
Wash your hands!
106.
Which of the following types of radiation has the most penetration power? Alpha, beta, or gamma
Gamma radiation
10
107.
What are the symbols used to represent an alpha particle, a beta particle, and a gamma ray?
Alpha α
4
He
2
Beta β
0
e
-1
Gamma
108.
What two particles make up a neutron?
Proton and electron
109.
What is the charge of an alpha particle, a beta particle, and a gamma ray?
Alpha particle +2
Beta particle -1
Gamma ray has no charge
110.
What type of material would help to shield you from the effects of gamma rays?beta particles? Alpha?
You need thick lead or concrete to shield yourself from gamma rays.
You need materials like plastic, glass, or wood to shield yourself from beta radiation.
You need paper to shield yourself from alpha radiation.
111.
What is fusion? Where does this process occur?
Fusion occurs in stars where there is sufficiently high temperatures and pressure. Small nuclei undergo
fusion when they join together to form larger nuclei. This process releases enormous amounts of
energy.
112.
What is fission? How is this process started?
Fission occurs when a large nuclei breaks into two smaller daughter nuclei. This process is triggered by
shooting a neutron at an atom of Uranium-235. The mass increases to 236 and the nucleus becomes
unstable. The nucleus then breaks apart and releases an enormous amount of energy.
113.
Which process is responsible for the creation of the elements?
Fusion
114.
What particle is needed to complete the following nuclear equation?
209
Po
84
4

He
2
205
+
Pb
82
115.
What particle is needed to complete the following nuclear equation?
45
0
45
Ca 
e +
Sc
20
-1
21
116.
What particle is needed to complete the following nuclear equation?
22
0
22
Na 
e +
Ne
10
-1
11
117.
What particle is needed to complete the following nuclear equation?
238
4
234
U 
He
+
Th
92
2
90
11