UNIT 5A OBJECTIVES -- ATOMS and the PERIODIC TABLE
At the conclusion of this unit, students will be able to:
Describe the historical progression of the atomic theory (AT).
Explain that science exists in a historical context.
Relate the development of the AT to its historical context.
Describe individuals and their contributions to the AT.
Describe the various models of the atom.
Describe the particles that make up atoms.
Describe similarities and differences of isotopes.
Determine atomic #, mass #, and particles in assigned isotopes.
Determine names and symbols of isotopes.
Determine average atomic mass of an element.
Explain relative abundances of isotopes.
Define orbital.
Describe shapes and sizes of various orbitals.
Identify the valence electrons for a given atom.
State the octet rule.
Define ion.
Describe how ions are formed.
Draw electron dot diagrams.
PHYSICAL SCIENCE – ATOMS AND THE PERIODIC TABLE
1. Indicate the chemical symbol for each of the following elements:
oxygen ______fluorine ______iron ______
silicon ______tungsten ______tin ______
2. Indicate which element is represented by each symbol:
Ne ______P ______Ca ______
Hg ______Pt ______C ______
3. The idea that matter is made of tiny particles called
"atoms" was first proposed by the Greek philosopher ______.
4. The Greek word "atomos" can be translated as ______.
5. Atoms are composed of: ______, ______, and ______.
5B. Of these, which one determines the chemical behavior of a given atom? ______
5C. The chemistry of an atom is determined by its ______. EXPLAIN WHY:
6. Complete the table of subatomic particles:
NAME / SYMBOLS / CHARGE / MASS NUMBER / RELATIVE MASS (amu) / WHERE FOUND6A. Of these, which one ABSOLUTELY determines which element an atom is? ______
6B. Define ATOMIC NUMBER:
7. The atomic number of an atom (element) is the number of ______.
8. For any neutral atom, the numbers of ______and ______are equal.
9. The ______determine the chemical behavior of an atom (element).
10. More specifically, the ______electrons determine the chemistry of an atom.
11. Describe what is meant by a "scientific model:"
12. In ______, Rutherford discovered that almost all of the atom’s mass, and all of its positive charge, is concentrated in the center, which he named the ______.
13. In other words, most of the atom is ______.
14. If an atom were the size of Three Rivers Stadium, its nucleus would be the size of a ______.
15. Describe Bohr’s model of the atom (also known as the ______model):
16. The best model of the atom is referred to as the electron ______or ______model of the atom.
17. Can we describe the motion of the electron in the atom? _____
Instead, we can only refer to the ______of finding the electron at any given location.
18. Your text suggests visualizing the electron cloud as similar to ______. A better suggestion is to think of the electrons as bees located around a central beehive (the nucleus).
19. Can electrons in atoms have "any old"
energy, or must they be at specific energy levels? ______
20. The lowest energy that a
particular electron can be at is called its ______state.
21. Higher electron energy levels are referred to as ______states.
22. When an electron "moves" from a higher to a lower energy level it releases its excess energy as a ______of ______radiation.
23. ______is the identification of substances by the specific energies of electromagnetic radiation that are absorbed or given off.
PHYSICAL SCIENCE – ATOMS AND THE PERIODIC TABLE
Pages 3 and 4
1. Examine the visual on page 108. Can you come up with a formula to predict the maximum number of electrons that can exist on any given energy level?
2. Use your formula to predict how many electrons can exist on the 5th (____ electrons) and 6th (____ electrons) energy levels.
3. Again, look at the visual on 108, and compare to the p orbital on 109. The picture on 108 looks like a fuzzy version of Bohr’s old ______model of the atom, with atoms limited to particular distances from the nucleus. Is that even possible, given the shape of a p orbital? ______Explain:
4. Define orbital:
5. Our modern model of the atom goes by many names:
Electron ______model
Electron ______model
______distribution model
______mechanical model
6. Describe the shapes of each kind of orbital:
s:
p:
d:
f:
7. Each individual orbital can hold a maximum of ____ electrons.
8. A given orbital has a name such as 2px. Indicate what each piece of the name tells us:
Number (s. a. 2 in 2px)
Letter (s. a. p in 2px)
Subscript (s. a. x in 2px)
1. For now, skip pages 111-115, except for giving the main idea of these 2 sections:
pp. 111-114: ______p. 115: ______
Now read and take notes on pages116-119.
2. Define ATOMIC NUMBER:
3. Complete the following:
The atomic number of carbon is ______.
All atoms of iron contain ______protons.
Atoms of ______contain 92 protons.
4. Define MASS NUMBER:
5. Imagine an atom composed of 15 protons, 15 electrons, and 16 neutrons. Complete the following:
atomic number: ______mass number: ______
Identify this atom: ______Symbol: ______
6. Now, imagine an atom composed of 15 protons, 15 electrons, and 17 neutrons. Complete the following:
atomic number: ______mass number: ______
Identify this atom: ______Symbol: ______
7. 31P and 32P are two ______of phosphorous.
8. Name the atom (isotope) that contains 20 protons, 20 electrons, and 22 neutrons:
Name: ______Symbol: ______
9. Name the atom (isotope) that contains 47 protons, 47 electrons, and 52 neutrons:
Name: ______Symbol: ______
10. Define: ISOTOPE:
PHYSICAL SCIENCE – ATOMS AND THE PERIODIC TABLE
Pages 5 and 6
1. Isotopes are named by their element name and mass number, such as boron-11 (11B), sodium-23 (23Na), and copper- 63 (______).
2. Cobalt-60 (60Co) is often used for radiation therapy. Atoms of this isotope are composed of ___ protons, ___ electrons, and __ neutrons.
3. The substance ______is often used for nuclear weapons. Atoms of this isotope are composed of 94 protons, ___ electrons, and 145 neutrons.
4. A particular isotope of copper is called Copper-63 (63Cu). Atoms of this isotope contain ___ protons, ___ electrons, and ___ neutrons.
5. Complete the chart of isotopes:
Name / symbol / atomic # / mass # / # protons / # electrons / # neutronsSulfur-35
Lithium-7
31P
22 / 24
122 / 52
238U
17 / 21
212Po
42 / 55
6. Atoms of the isotope 64Ga contain ____ electrons, ___ protons, and ___ neutrons. This isotope has a mass number of ____ and an atomic number of ____.
7. How can the number of neutrons in a particular atom be computed?
QUICK REVIEW:
8. Electrons have a charge of ______, a mass of ______, and are found ______the nucleus.
9. Protons have a charge of ______and a mass of _____, and are found ______the nucleus.
10. Neutrons have a charge of _____ and a mass of ______, and are found ______the nucleus.
11. The chemistry of an atom is determined by its ______.
12. Carbon occurs in nature as a mixture of two isotopes: carbon-12 and carbon-13. (For now, we will ignore the small amount of carbon-14 that is also present).
A. How are atoms of these isotopes the same?
B. How are atoms of these isotopes different?
13. Oxygen occurs in nature as a mix of two isotopes: 16O and 17O. Look at the periodic table -- the average atomic mass of oxygen is ______. Which isotope of oxygen do you think is:
less than 1% of naturally occuring oxygen? ______
more than 99% of naturally occuring oxygen? ______
14. Neon occurs in nature as a mixture of two isotopes: neon-20 and neon-22.
A. For a mix of 50% neon-20 and 50% neon-22 the "average atomic mass" would be ______. For a mix of 1% neon-20 and 99% neon-22 the "average atomic mass" would be (approximately) _____.
B. Look at the periodic table. The average atomic mass of neon is ______. What does this tell you about the ratio of neon-20 and neon-22 present in naturally occuring neon?
15. Define: AVERAGE ATOMIC MASS:
PHYSICAL SCIENCE – ATOMS AND THE PERIODIC TABLE
Pages 7 and 8
USE COMPLETE SENTENCES TO ANSWER THE FOLLOWING ITEMS (Unless asked to list, show, or calculate.)
1. How many outer electrons do atoms of each of the following have?
Neon ___ chlorine ____ sodium _____ oxygen _____
2. Show electron dot structures for the following atoms:
C Si Na K O S Ne
3. Explain what determines the chemical behavior of atoms:
4. Explain why we would expect atoms of F, Br, Cl, and I to behave similarly:
5. How (what) did Mendeleev contribute to the modern periodic table?
6. How (what) did Moseley contribute to the modern periodic table?
7. State the Periodic Law:
8. Define "Periodic Table."
9. Define (and match up) the following terms: period, row, column, group, family.
A.
B.
10. List the noble gases: ______
11. Why are they called the noble gases?
12. These noble gases are also called the ______or ______gases.
13. What chemical trait do the noble gases share? Why do the noble gases have such similar chemical behavior? Explain.
14. ______determine the chemical behavior of atoms.
15. Show the electron dot structures of the following atoms:
F P Li Ca N I O
16. The chemistry of atoms is determined by their ______, more specifically, it is determined by their ______electrons.
PHYSICAL SCIENCE – ATOMS AND THE PERIODIC TABLE
Pages 9 and 10
For each of the following periodic tables, complete the task assigned.
1. Draw the line separating the metals and nonmetals. Using three colors, color metals, nonmetals, and metalloids. Create a key.
2. Using various colors, color the alkali metals, alkaline earth metals, halogens, and noble gases. Create a key.
3. Using various colors, color the alkali metals, alkaline earth metals, transition metals, inner transition metals,and “other metals.” Create a key.
4. Suggest three questions for the upcoming test:
A.
B.
C.
Isotope / Mass (u) / Half-life / Mode of decay / Nuclear spin52Fe / 51.94812 / 8.28 h / EC to 52Mn / 0
53Fe / 52.945312 / 8.51 m / EC to 53Mn / 7/2
55Fe / 54.938298 / 2.73 y / EC to 55Mn / 3/2
59Fe / 58.934880 / 44.51 d / β- to 59Co / 3/2
60Fe / 59.934077 / 1.5 x 106 y / β- to 60Co / 0
61Fe / 60.93675 / 6.0 m / β- to 61Co
62Fe / 61.93677 / 68 s / β- to 62Co / 0
Isotope / Mass (u) / Half-life / Mode of decay / Nuclear spin
120I / 119.91005 / 1.35 h / EC to 120Te / 2
121I / 120.90737 / 2.12 h / EC to 121Te / 5/2
122I / 121.90760 / 3.6 m / EC to 122Te / 1
123I / 122.905605 / 13.2 h / EC to 123Te / 5/2
124I / 123.906211 / 4.18 d / EC to 124Te / 2
125I / 124.904624 / 59.4 d / EC to 125Te / 5/2
126I / 125.905619 / 13.0 d / EC to 126Te; β- to 126Xe / 2
128I / 127.905805 / 25.0 m / EC to 128Te; β- to 128Xe / 1
129I / 128.904988 / 1.7 x 107 y / β- to 129Xe / 7/2
130I / 129.906674 / 12.36 h / β- to 130Xe / 5
131I / 130.906125 / 8.040 d / β- to 131Xe / 7/2
132I / 131.90800 / 2.28 h / β- to 132Xe / 4
133I / 132.90781 / 20.8 h / β- to 133Xe / 7/2
134I / 133.9099 / 52.6 m / β- to 134Xe / 4
135I / 134.91005 / 6.57 h / β- to 135Xe / 7/2
Isotope / Mass (u) / Half-life / Mode of decay / Nuclear spin
41Ca / 40.9622783 / 102000 y / EC to 41K / 7/2
45Ca / 44.956186 / 162.7 d / β- to 45Sc / 7/2
47Ca / 46.954546 / 4.536 d / β- to 47Sc / 7/2
49Ca / 48.955673 / 8.72 m / β- to 49Sc / 3/2
50Ca / 49.95752 / 14 s / β- to 50Sc / 0
51Ca / 50.9615 / 10 s / β- to 51Sc; β- + n to 50Sc / 3/2
52Ca / 51.9651 / 4.6 s / β- to 52Sc
Isotope / Atomic mass (ma/u) / Natural abundance (atom %) / Nuclear spin (I)
54Fe / 53.9396127 (15) / 5.845 (35) / 0
56Fe / 55.9349393 (16) / 91.754 (36) / 0
57Fe / 56.9353958 (16) / 2.119 (10) / 1/2
58Fe / 57.9332773 (16) / 0.282 (4) / 0
http://www.webelements.com/iron/isotopes.html
"A new, improved version of the periodic table" NAME______
Read the article and answer the following questions:
1. Which American scientist created
several of the trans-uranium elements? ______
2. How was this scientist honored in 1951?______
3. How is this same scientist now being honored?
4. Explain how a cyclotron ("collider", "accelerator") is used to produce new elements:
5. Three groups claimed credit for discovering new elements. Which two organizations resolved the disputes?
______
______
6. According to the article, what determines the chemical behavior of an element?
7. If an atom of potassium-40 was smashed into a "target" atom of uranium-238, what atom would result?
potassium-40 plus uranium-238 yields ______
___ p+, ___ no + ____ p+, ____ no -----> ______
40K + 238U ----> ______
8. Assume you are working as a scientist at an accelerator, and successfully strike plutonium-239 target atoms with calcium-42 atoms. Here, show the equations (as above in #7) for this process:
9. From #8. REMEMBER -- YOU DISCOVERED IT!! Write a 100-200 word press release for the newspaper, describing what you did and what you discovered.