Unit 3 Review - Atomic Structure & Periodic Table
Part 1: Answer the following questions.
1. a. Which scientist created the first modern atomic theory? _John Dalton___
b. What was his theory?
1. All matter is made of extremely small particles called atoms
2. All atoms of a given element are identical and atoms of a specific element are different from any other element
3. Atoms cannot be created, divided into smaller particles or destroyed
4. Different atoms combine in simple whole number rations to form compounds
5. In a chemical reaction, atoms are separated, combined or rearranged.
c. What was his model of the atom called? __Billiard Ball____________________
d. What was proven wrong and why?
1. All atoms of a given element are identical – wrong b/c of the existence of isotopes
2.Atoms cannot be divided into smaller particles – wrong b/c of the existence of electrons, protons and neutrons
2. a. Which scientist did the gold foil experiment? _Rutherford_________
b. What did he conclude from the gold foil experiment?
1.Atoms are made up of mostly empty space
2.Atoms have a small positive center call the nucleus
3. a. Who discovered the electron? _J. J. Thomson__________
b. What was the name of his experiment? _Cathode Ray Tube Experiment____
c. What was his model of the atom called? _Plum Pudding Model_
4. What did Mendeleev do?
Arranged the periodic table in order of increasing atomic mass
5. a. Who arranged the modern periodic table? __Moseley_______
b. How is the modern periodic table arranged? Arranged in order of Atomic Number
6. a. What are the three subatomic particles? Give the symbols, charge, mass and location of each.
Particles
Proton
Neutron
Electron
Symbol
p+
no
e-
Charge
Positive
Neutral
Negative
Mass
1 amu
1 amu
1/2000 amu
Location
Nucleus
Nucleus
Electon Cloud
7
.
7. What is special about the proton? The proton IDENTIFIES THE ELEMENT
8. Fill in the blanks in the following:
a. Mass # = p+ + no
b. Atomic # = # of protons
9. What is the difference between Average Atomic mass and mass #? (Average) Atomic Mass is found on the periodic
table and is the weighted average of the isotopes. The Mass Number is the mass of one element and must be given or
calculated by adding the protons and neutron of that element.
10. Which of the following are isotopes of the same element? How do you know?
A. and D. They have the same
Atomic Number (# of Protons)
11. Calculate the average atomic mass for Boron if it has two naturally occurring isotopes: boron -10 (abundance
of 19.8%) and boron - 11 (abundance of 80.2%).
19.8
( 10 x 100 ) + ( 11 x
80.2
100
) = 10.802 amu
12. Identify an element "X" by calculating the average atomic mass. X - 6 (abundance of 7.5%) and X- 7 (abundance 92.5%).
7.5
( 6 x 100 ) + ( 7 x
92.5
100
) = 6.925 amu
Which is Lithium
13. a. Write the isotope notation in two ways (name and symbol) for the two carbon isotopes with masses of 12 & 14.
(1) Carbon - 12
12 C
(2) Carbon - 14
12 C
6
6
b. List all that is the same and all that is different between the two carbon isotopes. Same: Atomic # & # of p+s,
Different: # of neutrons & mass numbers.
14. On the periodic table below, label number of valence electrons at the top of each group.
1
8
2
3 4 5 6 7
2
b. Identify the following using the numbers from the periodic table above.
_1_Alkali Metals
_5_Noble Gases
_2_Alkaline Earth Metals
_6_Inner Transition metals
_4_Halogens
_3_Transition metals
c. What is a period on the periodic table? _an (horizontal) row_ How many periods are there? __7_
d. What is a group or family on the periodic table? _a (verticle) column____ How many groups are there? __18__
e. Where are most of the nonmetals located? To the right of the stairstep line
f. Where are most of the metals located? To the left of the stairstep line
g. The metalloids are located on either side of the _stairstep______ except for __Aluminum______.
17. a. Po and Bi are in the same. _Period________
b. Po and Te are in the same. __Group/family____
c. Name the metal that is in Group 13 and Period 5. __In - Indium___
d. Name the nonmetal in Group 16 and Period 2. __O - Oxygen____
e. Name the metalloid in Group 13 and Period 2 __B - Boron______
18. List all the properties of metals? Shiny, lustrous, conductor, malleable, ductile, high melting point and boiling point
19. List all the properties of non-metals? Dull, brittle, non-conductor, low melting point and boiling point
20. List all the properties of metalloids? Semi-conductor (has properties of metals and non-metals)
21. What is an ion? An atom with a charge
22. a. What is a positive ion called? _a Cation_____
b. In a positive ion, the number of protons is _greater than__the number of electrons.
24. a. What is a negative ion called?___an Anion_______
b. In a negative ion, the number of protons is _less than__ the number of electrons.
26. Draw the Lewis Dot Structure for Carbon, Sodium, Helium, & Neon.
27. What do the dots in a Lewis Dot structure represent? Valence Electrons
28. What are valence electrons? Electrons in the outer energy level
Nuclear Chemistry –Review
Fill-in-the-blank. Use the word bank to choose a word that best completes each statement.
Each word is used only once.
Word Bank:
alpha particle
radioactive decay
radioisotopes
alpha radiation
beta particle
photons
nuclear equation
gamma radiation
massive
half-life
nuclear reaction
bombardment
radiation
transuranium elements
fission
fusion
positron
beta radiation
transmutation
Geiger counter
1. _Bombardment_______ is striking nuclei with high-velocity charged particles to change one element
into another element.
2. Unstable chemical elements with atomic numbers greater than 92 are called __transuranium elements__.
3. _ Half-life __is the amount of time it takes for half of a radioactive substance to decay.
4. The beta particle represented by 01β is called a __ positron _______.
5. A nuclear reaction that joins atoms together producing a heavier atom and energy is known as _ fusion _.
6. Beta particles have greater energy but are less _ massive __ than alpha particles.
7. The type of radiation that can be stopped by a piece of aluminum foil is known as _ beta radiation _.
8. A(n) _ alpha particle _____ is also known as a helium nuclei.
9. Isotopes of atoms that have unstable nuclei, _ radioisotopes _, emit radiation to become more stable.
10. A _ Geiger counter ____ is a type of particle detector that detects the emission of nuclear radiation.
11. A _ nuclear reaction ___involves a change in the nucleus of an atom.
12. A __ nuclear equation ___ is used to represent a nuclear reaction, showing the atomic number and
the mass number of the particles involved.
13. A nuclear reaction that splits the nucleus of an atom forming different atoms and heat energy is known as _
fission _.
14. During _ radioactive decay __, unstable atoms lose energy by emitting one of several types of radiation.
15. The type of radiation that contains the most energy and can be slowed only by thick lead or concrete walls is
known as _ gamma radiation __.
16. The type of radiation composed of particles that have a charge of +2 is known as _ alpha radiation _.
17. Gamma radiation is composed of _ photons ___.
18. The rays and particles emitted by a radioactive source is called _ radiation _.
19. A _ beta particle ___is an electron with a charge of -1.
20. Induced transmutation occurs when chemists change one element into another by bombardment.
Types of Decay Reactions
State whether each of the following decay reactions is: alpha #3, beta #2, or gamma #1.
1.
2.
3.
Fill in the table below and then use it to figure out what is happening during each type of decay:
4. What changes take place in the nucleus when an alpha particle is emitted? 2 Protons and 2 Neutrons are lost.
4
5. What is the identity of an alpha particle? An Helium nucleus
2
H
6.
What changes take place in the nucleus when a beta particle is emitted? A Neutron is broken into electron & proton.
Proton kept and electron released.
Fill in the missing parts of these nuclear reactions: (numbers & elements)
7.
Show the alpha decay of radon – 198
8. Show the beta decay of uranium – 237
9. Plutonium – 244 undergoes gamma decay. What are the products of this reaction?
And a photon
10. Does the identity of an atom change during radioactive decay? Why or why not? For alpha and beta decay it does
because the proton number changes. During gamma, there is no change of identity, just energy.
11. List the 3 types of radiation (β, γ, α) in order from least penetrating to most penetrating and give how you block
each type.
1. α Alpha – can be blocked with paper
2. β Beta – can be blocked with aluminum foil
3. γ Gamma – can be blocked with lead or concrete
12. How does the “law of Conservation of Mass” explain how you write nuclear equations? The mass # and the Atomic
number have to be the same (add up to the same) on both sides of the yield (
) sign.