* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 17 Resource: Properties of Atoms and the Periodic Table
Survey
Document related concepts
Transcript
Glencoe Science Chapter Resources Properties of Atoms and the Periodic Table Includes: Reproducible Student Pages ASSESSMENT TRANSPARENCY ACTIVITIES ✔ Chapter Tests ✔ Section Focus Activity ✔ Chapter Review ✔ Teaching Transparency Activity ✔ Assessment Transparency Activity HANDS-ON ACTIVITIES ✔ Lab Worksheets for each Student Edition Activity Teacher Support and Planning ✔ Laboratory Activities ✔ Content Outline for Teaching ✔ Foldables–Reading and Study Skills activity sheet ✔ Spanish Resources ✔ Teacher Guide and Answers MEETING INDIVIDUAL NEEDS ✔ Directed Reading for Content Mastery ✔ Directed Reading for Content Mastery in Spanish ✔ Reinforcement ✔ Enrichment ✔ Note-taking Worksheets Name Date Directed ContentReading for MasteryMastery Content Class Overview Properties of Atoms and the Periodic Table Directions: Complete the concept map using the terms in the list below. Terms can be used more than once. protons periodic table electrons neutrons have a mass number equal to the sum of are made up of 1. and Meeting Individual Needs Atoms are organized as elements in the 5. 4. 2. and Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. and 6. 3. Directions: complete the following sentences by underlining the correct words in parentheses. 7. An element is matter that is composed of one type of (atom/quark). 8. The unit of measurement used for atomic particles is the (atom size/atomic mass unit). 9. Atoms of the same element that have different numbers of neutrons are called (isotopes/electron clouds). 10. In the periodic table, elements are arranged by increasing atomic (power/number). 11. An electron dot diagram uses the symbol of an element and dots to represent the (quarks/electrons) in the outer energy level. Properties of Atoms and the Periodic Table 19 Name Date Directed Reading for Content Mastery Section 1 ■ Section 2 ■ Class Structure of the Atom Masses of Atoms Directions: Use the terms below to complete the following paragraphs about atoms , atomic mass, and isotopes. Terms may be used more than once. six number electrons isotopes electron cloud neutron(s) proton(s) mass quarks six protons The electron has very little mass compared to the 1. ________________ or many 3. ________________ and 4. ________________ it has. The sum of the protons and neutrons is the mass 5. ________________ of an atom. The number of neutrons in an atom can be found by subtracting the atomic number from the 6. ________________ number. The mass of the atom is so small that there is a measure called the atomic 7. ________________ unit designated by amu. 8. ________________ and 9. ________________ make up the nucleus and are made up of 10. ________________. There are 11. ________________ uniquely different quarks. 12. ________________ are found in an area around the nucleus called the 13. ________________. The nuclei of all atoms of a given element always have the same number of 14. ________________. They will also have the same number of 15. ________________ around the nucleus. Some atoms may have more or fewer 16. ________________ than will other atoms of the same element. Atoms of the same element with different numbers of neutrons are called 17. ________________. Every atom of carbon must contain 18. ________________ but some contain six neutrons and others have eight neutrons. 20 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Meeting Individual Needs 2. ________________. The mass of the atom depends on the nucleus and how Name Date Directed Reading for Content Mastery Section 3 ■ Class The Periodic Table Periodic Table of the Elements Key 1 2 3 4 H Hydrogen 1.008 2 3 4 7 Carbon 12.011 2 13 14 15 16 5 6 7 8 He 17 Helium 4.003 9 10 Li Be Beryllium 9.0122 B C N O F Ne Boron 10.81 Carbon 12.011 Nitrogen 14.007 Oxygen 15.999 Fluorine 18.998 Neon 20.180 11 12 13 14 15 16 17 18 Al Si P S Cl Ar Aluminum 26.98 Silicon 28.086 Phosphorus 30.974 Sulfur 32.06 Chlorine 35.453 Argon 39.948 Na Mg Sodium 22.990 Magnesium 24.305 3 4 5 6 7 8 9 10 11 19 20 21 22 23 24 25 26 27 28 29 30 Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Iron 55.847 Cobalt 58.9332 Nickel 58.693 Copper 63.546 Zinc 65.39 Gallium 69.72 Germanium 72.61 Arsenic 74.922 Selenium 78.96 Bromine 79.904 Krypton 83.80 K Ca Sc Ti V Potassium 39.098 Calcium 40.078 Scandium 44.956 Titanium 47.88 Vanadium 50.94 38 39 40 Sr Y Zr Nb Strontium 87.62 Yttrium 88.9059 Zirconium 91.224 Niobium 92.91 57 56 La Cs Ba Cesium 132.905 Barium 137.327 Lanthanum 138.906 Chromium Manganese 51.996 54.938 41 Rb Rubidium 85.468 55 6 C Lithium 6.941 37 5 18 Atomic number Element's symbol Element's name Atomic mass 6 1 72 42 43 44 Mo Tc Ru Molybdenum Technetium Ruthenium 97.907 101.07 95.94 73 74 75 76 45 47 31 48 32 33 36 49 50 Pd Ag Cd In Sn Sb Te I Xe Palladium 106.42 Silver 107.868 Cadmium 112.41 Indium 114.82 Tin 118.710 Antimony 121.757 Tellurium 127.60 Iodine 126.904 Xenon 131.29 83 52 35 Rh 80 51 34 Rhodium 102.906 77 46 12 84 53 54 78 79 81 82 Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Hafnium 178.49 Tantalum 180.95 Tungsten 183.85 Rhenium 186.207 Osmium 190.2 Iridium 192.22 Platinum 195.08 Gold 196.967 Mercury 200.59 Thallium 204.383 Lead 207.2 Bismuth 208.98 Polonium 208.982 Astatine 209.987 85 Radon 222.018 86 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 Fr Ra Rf Db Sg Bh Hs Mt Uun Uuu Uub Uuq Uuh Uuo Francium 223.020 Radium 226.025 Ac Actinium 227.028 Rutherfordium (261) Dubnium (262) Seaborgium (263) Bohrium (262) Hassium (265) Meitnerium (266) Ununnilium (269) Unununium (272) Unumbium (277) Ununquadium (285) Ununhexium (289) Ununodium (293) Rare-Earth Elements 58 Lanthanide Series Ce Cerium 104.115 90 Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Actinide Series 59 60 61 62 Pr Nd Pm Sm Praseodymium Neodymium Promethium Samarium 150.36 63 64 Eu Gd Europium Gadolinium 151.965 157.25 140.908 144.24 144.913 91 92 93 94 95 Np Pu Am Th Pa U Thorium 232.038 Protactinium 231.036 Uranium 238.029 Neptunium Plutonium Americium 237.048 244.064 243.061 96 Cm Curium 247.070 65 Tb Terbium 158.925 66 67 Dy Ho Dysprosium Holmium 162.50 164.93 68 69 70 71 Er Tm Yb Lu Erbium 167.26 Thulium 168.934 Ytterbium 173.04 Lutetium 174.967 97 98 99 100 101 102 Bk Cf Es Fm Md No Berkelium Californium Einsteinium Fermium Mendelevium Nobelium 247.070 251.080 252.083 257.095 259.101 258.099 103 Lr Lawrencium 260.105 Directions: Use the periodic table above to answer the following questions. 1. List two types of information that are given in each box of this periodic table. a. b. 2. In this table, where are the metals located? 3. Where are the nonmetals located? 4. What are the elements in Groups 3 through 12 called? 5. What are the elements called that are next to the stairstep-shaped line on the right side of the table? 6. What do we call the letter or letters that represents an element? 7. How many elements are included in the modern periodic table? 8. What name is given to the elements in Group 18? Properties of Atoms and the Periodic Table 21 Meeting Individual Needs 1—New designation Name Date Directed Reading for Content Mastery Class Key Terms Properties of Atoms and the Periodic Table Directions: Match the term in Column II with the definition in Column I. Write the letter of the correct term in the blank at the left. Column I 1. sum of the number of protons and neutrons in the nucleus 3. positively charged center of an atom 4. vertical column in the periodic table 5. neutral particles in the nucleus of an atom 6. weighted average mass of the mixture of its isotopes a. nucleus b. electrons c. protons d. neutrons e. quark f. atomic number g. mass number 7. positively charged particles in an atom 8. table of the elements arranged according to repeated changes in properties 9. represents the electrons in the outer energy level of an element h. isotope i. average atomic mass j. electron cloud 10. negatively charged particles in an atom k. periodic table 11. atoms of the same element that have different numbers of neutrons l. atom 12. number of protons in an atom’s nucleus m. atomic mass unit 13. horizontal row in the periodic table n. group 14. smallest known particle that makes up protons and neutrons o. electron dot diagram 15. the smallest peice of matter that still retains the properties of the element p. period 16. developed an early periodic chart 17. approximately 1.67 ✕ 10-24g 22 Properties of Atoms and the Periodic Table q. Dmitri Mendeleev Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Meeting Individual Needs 2. region around the nucleus where the electrons are found Column II Name Date 1 Reinforcement Class Structure of the Atom Directions: Answer the following questions on the lines provided. 1. How is the chemical symbol of an element determined? Meeting Individual Needs 2. What are atoms composed of? 3. Are electrons, protons, or neutrons the smallest particles? If not, what are? 4. How many types of quarks are there and what is the name of one of them? Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. 5. Why do scientists use models to study atoms? 6. Why has the atomic model changed over time? 7. Why is the current atomic model called the “Electron Cloud Model”? Directions: Match the term in Column I with the definition in Column II. Write the letter of the correct definition in the blank at the left. Column I Column II 8. electron a. positively charged particle 9. neutron b. negatively charged particle 10. nucleus c. neutral particle 11. proton d. smaller particles that make up protons and neutrons e. positively charged center of an atom 12. quark Properties of Atoms and the Periodic Table 27 Name 2 Date Reinforcement Class Masses of Atoms Directions: Answer the following questions on the lines provided. 1. What are isotopes? 3. What is the average atomic mass of an element? 4. Compare and contrast the atomic structure of the chlorine-35 and chlorine-37 isotopes. 5. Suppose that a newly discovered element called centium has three isotopes that occur in nature. These are centium-200, centium-203, and centium-209. Assume that these isotopes occur in equal amounts in nature. What will be the average atomic mass of this element? 28 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Meeting Individual Needs 2. How do Boron-10 and Boron-11 differ? Name Date 3 Class The Periodic Table Reinforcement Directions: You will need a scientist’s patience to find the names of the 70 elements hidden in the grid. The lanthanides and the actinides have been excluded. The same letters may appear in more than one element name. Draw a line through the letters that correctly spell the name of an element. A Y M R A S S M R N U E B L U G N T N E I T T O N C A D M A I I L O M I I U M N I D N J E N Z E L I N E H L H G H P B R O M I N E D A P L N E H T U R C S P K L M U Y O P M Q R T S C M U V H E O H I Y D U R X E U A S C R N U R B D D P E N I E J I T I L B L F G O H O I H U P R H O R L E M O E N O D V P R D N L Q T K N D G A R T N R T H H A A H C N E D S T U H Y A H E M P E R B E N I N I O B I I U M O C N E E I I R U N T I D E T T A T S A A N A B E L E G O S C I S M U I N I T C A L C I U M M U I I I N I A I S I I A O G N L F F E A M L M T S L N D L N O C R I Z U U D N I A E N T T L I I A G H H L U L T P A S I M V E R U E E O T U U H I E N U L U N G C M N N R M Y M M R O R N T A H T U M S I B O R M M M O U G M L E I L D E U L M B O R O N M L E N N T S S M N O B R A C M E S U L U L H L N U H T Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. L U O R W S A Y X M D B Z K S F D E N O E O B O C E R G I I T U E I D B U P U T U N E T E I A H E L R N P L T I P E I U G M I L I R T T Y N T I I M N M I U U L M N R I U M V Y I F I A I U E M E C H R O M I U M A N L T S U O X Y G E N M E E A V U E R M U S E C M N B M K T I I R C E M N M D E S E N A G N A M A M P S I T R O N D T I V U M R A E N N E A D A N B E I U A R L A O H T M A U D R M E F D C M U A M U I M S O L D Directions: Complete the following paragraphs about the periodic table by filling each blank with the correct term. In the modern periodic table, elements are listed by increasing 1. ________________. Each box represents an 2. ________________. A box contains the name, atomic number, 3. ________________, and 4. ________________ for the element. Vertical columns in the table are called 5. ________________. Most elements in a column have the same number of 6. ________________ in the outer energy level and tend to have similar 7._________________. Horizontal rows in the table are called 8. ________________. The elements on the left side of the table are 9. ________________. Groups 3–12 contain metals known as 10. ________________. Elements on the right side are 11. ________________. Properties of Atoms and the Periodic Table 29 Meeting Individual Needs O O S I Name 1 Date Enrichment Class The Building Blocks of Matter From experiments involving the high-speed collision of particles, scientists have determined that heavy nuclear particles, such as protons and neutrons, are composed of quarks. The name “quark” was taken from a novel. Quarks are classified into six flavors—up, down, strange, charm, bottom, and top. The flavors are not related to any physical characteristics of the quarks themselves, but are used as classifications. Unlike protons and electrons, which carry whole charges of +1 or –1, quarks carry fractional charges. The following table lists some information about quarks. Quarks Symbol Charge Name Symbol Charge up u 2/3 down d 1/3 strange s 1/3 charm c 2/3 bottom b 1/3 top t 2/3 Mass 1. Use the library to find the name of the author and novel from which the word “quark” was taken. 2. Use the library to draw a time line showing the history of quarks. 3. Protons and neutrons are composed of triplets of up and down quarks. Use the information in the table to determine which of the following quark triplets represents a proton and which represents a neutron. udd __________________ uud __________________ 4. A heavier nuclear particle is composed of a triplet of strange quarks. What is the charge of this particle? 30 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Meeting Individual Needs Name Name Enrichment Class The Mole You have learned that the mass of atoms is measured in atomic mass units. This unit is too small to use in everyday measurement. It would be simpler to have a number of atoms that would have a mass in grams that is equal to the mass of one atom in atomic mass units. The same number would fit all elements, because equal numbers of different atoms always have the same mass ratio. Chemists have found that 6.02 ✕ 1023 atoms of an element have a mass in grams equivalent to the mass of one atom in atomic mass units. This counting unit is called a mole. For example, one mole of helium atoms has a mass of 4 grams because helium has a mass number of 4. Do you know how big a number a mole is? Suppose the entire population of the world, more than four billion people, were assigned to count the number of atoms in one mole of helium. If each person counted one atom per second and worked a 48-hour work week, the task would take more than 10 million years. If you had one mole of pennies, you would have enough money to pay all the expenses of the United States for the next billion years. 1. A mole is a certain number of items. What number does each of the following terms represent? a. dozen ______________ d. mole ______________ b. billion ______________ e. gross ______________ Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. c. million ______________ 2. Using a laboratory balance, measure and record the mass of one mole of each of the following elements: carbon, iron nails, zinc metal, and copper wire. 3. Find the mass, in grams, of each of the following: a. 2 moles of aluminum ______________ b. 4 moles of magnesium ______________ c. 3 moles of helium ______________ 4. How many moles are in each of the following: a. 156 grams of chromium ______________ b. 156 grams of potassium ______________ c. 119 grams of uranium ______________ 5. Why is the counting unit called a mole useful for chemists? Properties of Atoms and the Periodic Table 31 Meeting Individual Needs 2 Date Name 3 Date Enrichment Class Predicting an Element’s Group and Period Several scientists, including Newlands, Meyer, and Mendeleev worked on classification systems that grouped elements according to their properties. They found that these properties repeated in a regular or periodic manner. This fact was used to predict properties of undiscovered elements. Review electron arrangement from your textbook. In Table 1, write the maximum number of electrons that can fill each energy level on the blanks in the table heading. Write the total number of electrons for each element in the first column labeled Total. For each element, assign the correct number of electrons to each energy level. Complete Table 2 by using the information from the six elements studied. Electrons Element Total Level 1 Level 2 Level 3 Number of outer electrons Located in group 1. Argon 2. Carbon 3. Helium 4. Lithium 5. Silicon 6. Sodium Table 2 Element Energy level of outer electrons Located in period 7. Ar 8. C 9. He 10. Li 11. Si 12. Na 13. How is the element’s period related to the number of energy levels over which its electrons are spread? 14. How can you predict an element’s group and period? 32 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Meeting Individual Needs Table 1 Name Date Note-taking Worksheet Section 1 Class Properties of Atoms and the Periodic Table Structure of the Atom A. ____________ are abbreviated in scientific shorthand—first letter or two of element’s name B. ________—smallest piece of matter that still has the properties of the element 1. ___________ have electrical charge of 1+. 3. _____________ have electrical charge of 1-. 4. Protons and neutrons are in the ___________ of an atom; electrons surround the nucleus. C. Protons and neutrons are made up of smaller particles called __________. 1. Six quarks are known to exist; the sixth is called the _______ quark. D. Scientists use scaled-up __________ to represent atoms. 1. Early models of atoms used a solid __________. 2. Current __________________ model shows electrons traveling in specific energy levels around a nucleus of protons and neutrons. Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Section 2 Masses of Atoms A. _______________—composed mostly of the protons and neutrons in the nucleus 1. Unit of measurement for atomic particles is ____________________ (amu) which is one-twelfth the mass of a carbon atom containing six protons and six neutrons. 2. _________________—the number of protons in an atom; number of protons also identifies the element 3. The sum of the number of protons and neutrons in the nucleus of an atom is the _______________. B. ____________—atoms of the same element with different numbers of neutrons 1. Different isotopes have different ______________. 2. Number of ____________ is equal to mass number minus atomic number. 3. Name of ___________ followed by mass number identifies the isotope. 4. _______________________ is the weighted-average mass of an element’s isotopes. 5. Average atomic mass is closest to its most ____________ isotope. Properties of Atoms and the Periodic Table 33 Meeting Individual Needs 2. ____________ do not have an electrical charge. Name Date Class Note-taking Worksheet (continued) Section 3 The Periodic Table A. Elements are organized in the __________________ by increasing atomic number. 1. In the late 1800’s, Dmitri Medeleev devised the first periodic table based on _______________. 2. In 1913, Henry G. J. Moseley arranged the elements by _________________ rather than atomic mass. B. Vertical columns in the periodic table are __________ of elements with similar properties. 2. Each of the seven energy levels can have a ___________ number of electrons. a. Energy level one can contain at most _______ electrons. b. Energy level two can contain at most _________ electrons. 3. Each row in the periodic table ends when an outer energy level is __________. 4. _________________________ use the element symbol and dots to represent outer energy level electrons. C. ___________—horizontal rows of elements that contain increasing numbers of protons and electrons. 1. Elements are ______________ as metals, nonmetals, or metalloids (semimetals). 2. Elements are _______________ in laboratories all over the world. D. The ________ elements exist all over the universe. 1. Hydrogen and helium are the ___________________ of other naturally occurring elements. 2. ______________ spread heavier elements throughout the universe. 34 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Meeting Individual Needs 1. Elements in the same group have the same number of _____________ in their outer energy level. Name Date Class Properties of Atoms and the Periodic Table Chapter Review Part A. Vocabulary Review Directions: On the space at the left, write the term that correctly completes each statement. Use each term once. metals groups electrons chemical symbol isotopes metalloids nucleus average atomic mass electron cloud transition elements atomic number mass number periods quarks periodic table 1. A capital letter or a combination of a capital letter and a small letter that is used to represent an element is called a(n) ______. 2. The horizontal rows of elements are called ______. 3. An average of the masses of all the isotopes that occur in nature for an element is the ______. 4. Vertical columns of elements are called ______. 5. Elements in the middle of the periodic table, groups 4 through 7, are called the ______. 7. Protons and neutrons can be subdivided into ______ by colliding them. 8. The center of an atom where protons and neutrons are located is the ______. 9. A total count of the neutrons and protons in an atom is the ______. 10. Atoms of the same element but with different numbers of neutrons are ______. 11. Elements that are found on the left side of the periodic table are ______. 12. Elements that have some properties of both metals and nonmetals are ______. 13. The particles that move about the nucleus and have a negative charge are ______. 14. The region around the nucleus occupied by electrons is a(n) ______. 15. A chart that shows the classification of elements is called the ______. Properties of Atoms and the Periodic Table 37 Assessment Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. 6. The number of protons in an atom is the ______. Name Date Class Chapter Review (continued) Part B. Concept Review Directions: Complete the table below by writing the correct information in the blank spaces. Chemical symbol Element Atomic number Number of protons Number of neutrons Mass number 11 11 12 23 6 6 12 26 30 56 16 32 1. Sodium 2. Carbon C 3. Fe 26 4. Sulfur S 16 5. Nitrogen N 7 7 6. Oxygen O 8 8 8 7. He 2 2 2 8. Chlorine-35 Cl 17 17 9. Copper Cu 29 29 35 17 20 Cl 10. Chlorine-37 14 4 35 37 1 18 11 Assessment Na 2 13 14 15 16 17 23 26 3 A 4 5 6 7 8 9 10 11 12 C Fe Fe 55.8 79 Au 197 Au B 11. Which element has a greater atomic mass, A or B? 12. Which element is a metal, B or C? 13. In which group is gold? 14. What is the average atomic mass of iron? 15. What is the atomic number of sodium? 38 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Directions: Refer to the periodic table below and the boxes at the right of the table to answer questions 11–15. Name 1 Date Section Focus Transparency Activity Class Subatomic Collision Transparency Activities 1. Why do you think scientists have only recently discovered these subatomic particles? 2. What might scientists learn by breaking apart atomic nuclei? 44 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. An individual atom is so small that it would take 50 million of them lined up in a row to equal one centimeter! Atoms, however, can be divided into component parts, and, amazingly, some of these parts have particles that are tinier yet. Below is an image created by these subatomic particles taken in a device called a bubble chamber. Name 2 Date Section Focus Transparency Activity Class Carbon Cat Transparency Activities Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. How old are these mummified cats found in an Egyptian tomb? Carbon-14 holds the answer. Carbon-14 is a radioactive form of carbon, an element found in every living thing. By measuring how much carbon-14 remains in these cats, scientists can tell approximately how many years ago the cats were buried. 1. Carbon-14 decays over time. What does “decay” mean? 2. Why do you think carbon is used by scientists to date objects such as mummies, bones, and cloth wrappings? 3. Is it possible to use carbon-14 dating on things that were never alive? Why or why not? Properties of Atoms and the Periodic Table 45 Name 3 Date Section Focus Transparency Activity Class What makes the glass glow? 1. Of what materials is glass usually made? Transparency Activities 2. Why do you think the glass glows? 3. Why might prolonged work with such glass be dangerous? 46 Properties of Atoms and the Periodic Table Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. When you hear the word uranium, you might think of nuclear power. Uranium, though, was used in the 19th century by European glassmakers to create what was called uranium glass. This interesting glass had a yellowish-green color and glows under certain lighting conditions. Name Date 1 Teaching Transparency Activity Class Electron Cloud Model Nucleus Transparency Activities Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Electron cloud Properties of Atoms and the Periodic Table 47 Name Teaching Transparency Activity Date Class (continued) 1. What is the region around the nucleus called? 2. What was the name of the Greek who proposed the idea that atoms made up all substances? 3. What is an electron cloud? 4. What determines how far each electron travels from the nucleus? 5. Why can’t electron positions be pinpointed? Transparency Activities Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. 6. Electrons are located in a cloud surrounding what part of the atom? 48 Properties of Atoms and the Periodic Table Name Date Assessment Transparency Activity Class Properties of Atoms and the Periodic Table Directions: Carefully review the table and answer the following questions. Characteristics of Some Alkaline Earth Metals Atomic number Mass number Melting point (˚C) Boiling point (˚C) Magnesium 12 24 651 1105 Calcium 20 40 842 1494 Strontium 38 88 769 1384 Barium 56 137 725 1640 1. According to the table, which alkaline Earth metal has a mass number greater than 100? A Magnesium C Strontium B Calcium D Barium 2. According to the table, which element has the LOWEST atomic number? F Magnesium H Strontium G Calcium J Barium 3. According to the table, which element has the HIGHEST melting point? A Magnesium C Strontium B Calcium D Barium Transparency Activities Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Element 4. The number of neutrons in the nucleus of an atom is equal to the mass number minus the atomic number. According to this definition and the table, how many neutrons are in the nucleus of a strontium atom? F 20 G 38 H 50 J 81 Properties of Atoms and the Periodic Table 49