ELECTRON ARRANGEMENT AND THE PERIODIC TABLE



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|UNIT 2: Atomic Theory and Structure |

|Part D: The Periodic Table of the Elements |

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|Big Picture Idea: An element’s electronic structure determines its chemical and physical properties and therefore its placement on the |

|periodic table. |

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|Big Picture Question: How does the periodic table use physical and chemical properties to arrange the elements? |

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|Suggested Resources… |

|Homework Assignments |

|Classwork Assignments |

|Laboratory Activities |

|Formative Assessments |

|Textbook pages: Chapter 6 |

|Websites: |

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|Key Terms: |

|Mendeleev |

|Moseley |

|Periodic Law |

|period |

|group/family |

|Alkali Metals |

|Alkaline Earth Metals |

|Halogen |

|Nobel Gases |

|metals |

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|nonmetals |

|semimetals/metalloid |

|valence electrons |

|s,p,d,f blocks |

|atomic radius |

|ionic radius |

|ionization energy (+ ion) |

|electronegativity |

|transition metals |

|24. Lanthanide series |

|25. Actinide series |

|26. diatomic elements |

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|Directions: Use this information as a general reference tool to guide you through this unit. Don’t hesitate to ask your teacher for |

|help! |

|By the conclusion of this unit, you should know the following: |By the conclusion of this unit, you should be able to do the |

|Contributions of Moseley and Mendeleev in the development of the |following: |

|current periodic table. |Given a group of atoms, arrange them based on periodic trends. |

|Arrangement of periodic table based on electron configuration and |State the periodic law |

|names of groups/periods. |Know scientists and their contributions to the development of the |

|Group/Period trends for atomic radius, ionization energy, |Periodic Table |

|electronegativity, and metallic character based on atomic |Explain why elements in a group have similar properties |

|structure. |Identify the four blocks on the periodic table |

|Molar mass can be used to covert between grams, moles and molecules|Identify four important periodic trends and explain how each reflects |

|of a diatomic element. |the electron configurations of the elements |

| |Use dimensional analysis to convert between molecules, moles and grams|

| |of a diatomic element. |

Practice Problems:

1. What did Mendeleev contribute and how does this relate to Moseley?

2. What does the Periodic Law state?

3. Look at a periodic table- identify periods, groups, families, s block, p block, d block, f block, alkali metals, alkaline earth metals, halogens, noble gases, metals, semimetals, nonmetals, metalloids .

Draw arrows for ionization energy, atomic radius and electronegativity. Which element is highest for each?

4. Looking at electron configurations, what stays the same and what changes in a family (do it again for a period)?

5. What happens to ion size when ions gain electrons/ when they lose electrons?

6. Rank in order of increasing electronegativity a) Sr, K, Ca b) S, Se, Cl c) B, C, N d) Na, Li, K

7. Rank in order of atomic radius and explain why these trends happen a) Li, Be, B b) S, P, Cl c) Rb, K, Cs d) Na, K, Ca

8. Rank the ions in order of ionic radius, why do these trends happen a) Mg2+, Na+, Al3+ b) Ba2+, Ca2+, Sr2+ c) Se2-, O2-, S2- d) Mg2+, Mg, Ca e) S, S2-, O

9.Rank the atoms from lowest to highest ionization energy a) Cl, Br, Ar b) K, Rb, Na c) C, N, O d) Rb, Ba, Sr

10. Write the short hand electron configuration for element 19, element 53, element 88. Which families do they belong to and give electron dot structure.

11. Specify properties of m, nm, sm. Given an unknown element with some general properties can you identify it as a metal, non-metal, or semimetal?

12. List the diatomic elements.

13. a. Find the mass of 2.5 moles of nitrogen gas. B. How many molecules are in 50.0g of chlorine?

PERIODIC TABLE ELECTRON CONFIGURATION ACTIVITY

1. Complete the chart below.

2. Find the square corresponding to each element on the blank periodic table. Copy the last part of the electron configuration into the periodic table square.

3. Look for patterns, and fill in as many of the squares as you can.

|Element |Electron Configuration |Dot Diagram |

|Hydrogen | | |

|Helium | | |

|Lithium | | |

|Potassium | | |

|Francium | | |

|Beryllium | | |

|Magnesium | | |

|Barium | | |

|Vanadium | | |

|Chromium | | |

|Manganese | | |

|Zinc | | |

|Boron | | |

|Aluminum | | |

|Carbon | | |

|Germanium | | |

|Nitrogen | | |

|Flourine | | |

|Neon | | |

|Xenon | | |

Reading Electron Configuration Directly from the Periodic Table

Try:

Cesium

Strontium

Silicon

Argon

Chromium

Chlorine

Tin

Radium

Nickel

Palladium (Pd)

Antimony (Sb)

History:

Mendeleev – 1st periodic table (arranged elements by mass)

Moseley – revised periodic table (arranged by atomic number)

Periodic Law – the elements physical and chemical properties follow periodic (repeating) trends (based on their location of the periodic table) ***Patters repeat***

Parts of the Periodic Table:

Group/Family: column – same valence electrons or outer configuration

Period: row, same energy level

Metals: good conductor, solid @ room temp., shiny, ductile, malleable, form + ions

Non-Metals: poor conductor, solid/liquid/gas @ room temp., brittle, form - ions

Metalloids: elements that touch the staircase (except Al), have intermediate properties

Families

| |Reactivity |Ion Formation |Misc. |

|Alkali Metals |violently |+1 |Not found free in nature, e- |

| | | |configuration ends in s1 |

|Alkaline Earth Metals |very |+2 |e- configuration ends in s2 |

|Transition Metals |More stable |Form ions with more than one charge |Form colored solutions, d block |

|Inner Transition Metals |Many are radioactive |Varying charges |F block |

|Halogens |Most reactive nonmetals |-1 |Diatomic as elements, e- |

| | | |configuration ends in p5 |

|Noble Gases |stable |Do not form ions |Full valence electron shell, e- |

| | | |configuration ends in p6 |

Blocks

s block – 1st 2 columns on left side of the table

p block – last 6 columns on right side of the table

d block – middle 10 columns of the table

f block – lower (removed) 2 rows of the table

NOTES – PERIODIC TRENDS

Li F

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K

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|Definition |Down a Group |Across a Period |

|Atomic Radius – size of an atom (1/2 the distance |increases down a group because of more energy levels |elements gets smaller (stronger nuclear pull) |

|between 2 nuclei of different atoms) |and more shielding | |

|Ionization Energy - energy needed to remove an electron|Decreases down a group because the electron is far from|increases because nucleus is stronger, better protects |

|from an atom |the nucleus and shielding |electron |

|Electronegativity - ability of an atom to remove and |Decreases down a group because the electron is far from|increases because nucleus is stronger, better able to |

|electron from another atom |the nucleus and shielding from nucleus |take electrons (EXCEPT noble gases) |

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PROBLEMS:

1. Circle the member of each pair that has the greatest radius:

a. oxygen (O) or carbon (C) b. calcium (Ca) or barium (Ba)

c. magnesium (Mg) or phosphorus (P) d. strontium (Sr) or silver (Ag)

2. Arrange the elements below in order of increasing radius:

sodium (Na), potassium (K), nickel (Ni), bromine (Br)

Na ................
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