Topic # 7



Periodic Table

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Homework Due: _________________

Text Book: Read pages 63-69

Exam Dates: _____________________________

Periodic Table Student Outline

➢ Names and symbols of elements on Table S

➢ Periodic law

➢ Period is a horizontal row across the periodic table

➢ Group / family is a vertical column down the periodic table

Group 1 – Alkali metals

Group 2 – Alkaline earth metals

Group 17 - Halogens

Group18 – Noble Gases

Groups 3 - 11 Transition metals

➢ Reactivity of elements is dependent on valence electrons

➢ Characteristics of metals, non metals and metalloids

Metals non metals metalloids( semi-metals)

left of stairs right of stairs Seven Semimetals: on stairs

few valence electrons close to 8 valence electrons characteristics of both metals and

lose valence electrons gain valence electrons non- metals

solids except for Hg solids, liquids and gases semi-conductors become positive ions become negative ions include B, Si, Ge, As, Sb, Te, At

solids if solid, brittle and dull

conductor of electricity non conductors

malleable

ductile

shiny/have luster

➢ Transition metals

o Multiple oxidation states

o Can lose electrons from outermost 2 principle energy levels (PEL)

o Colored ions in solution

o Can form multiple compounds with the same element

➢ Atomic radius

➢ Ionic radius

➢ If an atom gains electrons its ion will be ….a negative ANION (-) and is larger than the atom

➢ If an atom loses electrons its ion will be …. a positive CATION (+) and is smaller than the atom

➢ To find the charge of an atom’s ion look it up on the reference table under “Selected Oxidation States”

➢ Periodic trends can be looked up in reference table S and the Periodic Table

Periodic trend Across a period Down a group

Atomic radius decrease increase

Ionization energy increase decrease

Electronegativity increase decrease

Metallic character decrease increase

Valence electrons changes remains the same

# of occupied energy levels remains the same increases

Atomic # increase by 1 increase

➢ Changes in periodic trends are due to …

➢ Number of PELs

➢ Nuclear hold (holding strength of the nucleus by the protons)

➢ Shielding effect ( the PELs between the nucleus and the valence electrons

➢ Identifying phases of elements at room temperature

➢ Predicting group locations from chemical formulas

GROUP 1 2 13 14 15 16 17 18

Charge in compounds +1 +2 +3 +4 or -4 -3 -2 -1 0

What you can find out from the periodic table:

1. Atomic mass of any element ( which is equal to the mass, in grams, of 1 mole of that substance.

2. Atomic number of any element which

• is equal to the number of protons in the nucleus =

(nuclear charge of the atom)

• and the number of electrons in the energy levels of an atom.

• Protons = electrons = atomic # …in any atom

3. Electron configuration of an atom – placement of electrons in the energy levels, sublevels and orbitals….determine half filled, occupied and filled.

4. Symbols of the elements and names on table S

5. Valence electrons ( all e- in outer most PEL… or “the trick” group its in)

6. Determine the kernel of the atom ( all parts except the valence e-)

7. The valence PEL is the period #

8. Group names: alkali (I), alkaline earth (II), transition metals, halogens (17), noble/ inert gases (18)

9. Location of the metals, non- metals and metalloids

10. Most metallic properties or most non- metallic properties

11. Radioactive elements … stable radioisotopes

12. Basis of the atomic masses ~~ carbon – 12 and the average of the most abundant isotopes of that element

13. Noble gases have a full outer (valence) shell , therefore not reactive … does not give or take electrons

14. Formation of ions from the atoms . metals = + (lose e- … become smaller) … non metals = - (gain e- … become larger)

15. Atomic mass = # of protons + # of neutrons… different mass represents an isotope (change in mass only)

16. Atomic # represents the atom or element .. the atomic # or the number of protons CANNOT change.

17. Determine the ground state and excited state of an atom

18. Can determine the electron dot diagrams from the # of valence e-

19. Determining the oxidation states (electrons lost or gained) by an atom.

20. Characteristics of transition elements: can lose e- from 2 outermost PEL’s , can form more that one type of compound formula, form colored solutions.

21. Locating the diatomic elements on the table (Br I N Cl H O F) most diatomics in group 17 ~ the halogens

22. Locating the phases of matter on the periodic table … (halogens have elements in all three phases)

• gases = (O, N, Cl, F , H, and Noble Gases/Group 18),

• liquids Hg (at STP, the only liquid metal) and Br (at STP, the only liquid nonmetal)

• solids (most elements on periodic table).

23. Elements are arranged on the periodic table according to atomic number (# of protons) not atomic mass

24. Period (horizontal row) – tells the valence shell, # of occupied PEL’s , # of e- increases from left to right.

25. Group /family vertical column with similar properties, same # of valence electrons, blocks tell the sublevels being filled

• Group 1 Alkali metals very reactive … become more reactive as you go down the group …

always occur combined with nonmetals in nature

• Group 2 Alkaline Earth Metals also reactive (not as reactive as group 1)

• Group 17 Halogens- all diatomic, contain elements in all 3 phases of matter.

• Group18 Noble Gases / Inert Gases -rarely bond except for Xe and Kr which can combine with F at high P and T

• (see periodic table for oxidation states) are unreactive ( have

either 8 valence electrons or a filled outer shell (remember about He)

• Groups 3 - 12 transition elements … colored ions and multiple oxidation

states, can lose electrons from inner and outermost energy levels. (Can form

more than one compound when bonding because of multiple oxidation

states)

26. Reactivity of elements …

• lower left = most reactive metals (greatest metallic character) They contain one or two valence electrons and as you move down the group there are more shells (lower down the group = most reactive) …

• upper right are the most reactive non metals (greatest nonmetallic character) (group 17; close to having 8 valence electrons or a full (stable) outermost shell)..These active elements do not occur alone/uncombined in nature.

27. Characteristics of metals , non metals and metalloids

28. The Periodic law – properties of the elements are periodic according to their atomic numbers

29. Who arranged the periodic Table – Dimitri Mendeleev

30. How is the periodic table arranged. According to atomic number …. Used to be according to atomic mass (notice discrepancies (example Cobalt and Nickel) … reorganized by atomic number … the number of protons in an atom)

33. Determining the Radii of atoms:

• Across a period the radii gets smaller due to greater nuclear charge, pulling the same # of shells closer together Nuclear hold (# of protons in nucleus) or

• Down a group the radii gets larger due to more shells in the atom Shielding effect ( # of shells between nucleus and valence electrons)

34. Ionic radius – produced when an atom forms an ion ( loses or gains electrons)

1. If an atom gains electrons (becomes - , typically non metals) its ion will be larger than the atom

2. If an atom loses electrons (becomes +, typically metals) its ion will be smaller than its atom

35. Periodic trends all can be looked up in the reference tables

Periodic Table Homework

A) Page 82 Introduction to Periodic Table

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B page 356 Atomic properties and the periodic table

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a ___________

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a ___________

b ___________

c ___________

d ___________

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a ______________________

b ______________________

c ______________________

C Complete the Following:

1. Who organized the periodic table? __________________________________________________

1. How many rows are on the current periodic table? _________________________

2. How many columns (groups) are on the current periodic table? _________________________

3. How is the periodic table arranged? _________________________

4. What are the two rows below the main body of the periodic table called? ____________________

5. Where are the nonmetals located on the periodic table? _________________________

6. Where are the metals located on the periodic table? _________________________

7. Where are the metalloids located on the periodic table? _________________________

8. Which columns contain transition metals? _________________________

9. Which column contains elements with completely filled p orbitals? _________________________

10. Which column contains elements whose electron configurations end with a d orbital? ___________

11. Where are the most active metals located on the periodic table? _________________________

12. Where are the most active nonmetals located on the periodic table? _________________________

13. Which is the most active nonmetal on the periodic table? _________________________

14. What happens to the ATOMIC RADIUS as you move across a period from left to right? ________

Why does this radius change? _________________________

15. What happens to the ATOMIC RADIUS as you move down a group from top to bottom? ________

Why does this change in radius occur? _________________________

16. When an atom becomes a negative ion, the original atom is

(smaller OR larger ) than the ion formed? _________________________

17. When an atom becomes a positive ion, the original atom is

(smaller OR larger ) than the ion formed? _________________________

18. What happens to the ionization energy as you move across a period from left to right? __________

Explain why? _________________________

19. What happens to the ionization energy as you move down a group from top to bottom? _________

Explain why? _________________________

20. What are the names of the following groups?

• Group 1 _______________________________________________________

• Group 2 _______________________________________________________

• Groups 3-12 _______________________________________________________

• Group 17 _______________________________________________________

• Group 18 _______________________________________________________

21. Elements within a group have the same number of _____________________________________

22. Elements within a period have the same number of _________________________

23. What are the “special” characteristics of transition elements?

• _________________________

• _________________________

• _________________________

24. What happens to the metallic character as you go down a group? _________________________

25. What happens to metallic character as you go across a period? _________________________

26. The majority of the elements on the periodic table are ( metals/nonmetals/metalloids) ___________

27. The majority of the elements on the periodic table are ( solids/liquids/gases) __________________

28. Elements on the periodic table are organized according to their_________________________

29. An element with properties of both metals and nonmetals is called_________________________

30. Why do group 18 elements have higher ionization energies and

NO electronegativity values? __________________________________________________

31. The vertical columns of the periodic table are called? _________________________

32. The horizontal rows of the periodic are called? ________________________

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

I | | | | | | | | | | | | | | | | | | | |F | | | | | | | | | | | | | |G |H | | | | | | | | | | | | | | | |B | | | |A | |C | | | | | | | |E | | | |J | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

Place the letter from the periodic table above next to the description that best matches that element:

a) an alkali metal

b) an inactive gas

c) a semimetal

d) a metal with more than one bonding possibility

e) an alkaline earth metal

f) an active nonmetal

g) a metal with 3 valence electrons

h) a nonmetal with 1 valence electron

20 facts you didn’t know about the Periodic table

~ Adapted online from Lawrence Berkeley National Lab

1. You’ll never guess its real purpose: It’s a giant cheat sheet.

2. The table has served chemistry students since 1869, when it was created by Dmitry Mendeleev, a cranky professor at the University of St. Petersburg.

3. With a publisher’s deadline looming, Mendeleyev didn’t have time to describe all 63 then-known elements. So he turned to a data set of atomic weights meticulously gathered by others.

4. To determine those weights, scientists had passed currents through various solutions to break them up into their constituent atoms. Responding to a battery’s polarity, the atoms of one element would go this away, the atoms of another that away. The atoms were collected in separate containers and then weighed.

5. From this process, chemists determined relative weights—which were all Mendeleyev needed to establish a useful ranking.

6. Fond of card games, he wrote the weight for each element on a separate index card and sorted them as in solitaire. Elements with similar properties formed a “suit” that he placed in columns ordered by ascending atomic weight.

7. Now he had a new Periodic Law (“Elements arranged according to the value of their atomic weights present a clear periodicity of properties”) that described one pattern for all 63 elements.

8. Where Mendeleeev’s table had blank spaces, he correctly predicted the weights and chemical behaviors of some missing elements—gallium, scandium, and germanium.

9. But when argon was discovered in 1894, it didn’t fit into any of Mendeleeev’s columns, so he denied its existence—as he did for helium, neon, krypton, xenon, and radon.

10. In 1902 he acknowledged he had not anticipated the existence of these overlooked, incredibly unreactive elements—the noble gases—which now constitute the entire eighth group of the table.

11. Now we sort elements by their number of protons, or “atomic number,” which determines an atom’s configuration of oppositely charged electrons and hence its chemical properties.

12. Noble gases (far right on the periodic table) have closed shells of electrons, which is why they are nearly inert.

13. Atomic love: Take a modern periodic table, cut out the complicated middle columns, and fold it once along the middle of the Group 4 elements. The groups that kiss have complementary electron structures and will combine with each other.

14. Sodium touches chlorine—table salt! You can predict other common compounds like potassium chloride, used in very large doses as part of a lethal injection.

15. The Group 4 elements (shown as IVA above) in the middle bond readily with each other and with themselves. Silicon + silicon + silicon ad infinitum links up into crystalline lattices, used to make semiconductors for computers.

16. Carbon atoms—also Group 4—bond in long chains and sugars. The chemical flexibility of carbon is what makes it the key molecule of life.

17. Mendeleyev wrongly assumed that all elements are unchanging. But radioactive atoms have unstable nuclei, meaning they can move around the chart. For example, uranium (element 92) gradually decays into a whole series of lighter elements, ending with lead (element 82).

18. Beyond the edge: Atoms with atomic numbers higher than 92 do not exist naturally, but they can be created by bombarding elements with other elements or pieces of them.

19. The two newest members of the periodic table, still-unnamed elements 114 and 116, were officially recognized last June. Number 116 decays and disappears in milliseconds. (Three elements, 110 to 112, were also officially named earlier this month.)

20. Physicist Richard Feynman once predicted that number 137 defines the table’s outer limit; adding any more protons would produce an energy that could be quantified only by an imaginary number, rendering element 138 and higher impossible. Maybe.

Questions:

1. State 2 facts from the periodic table you did not know

2. what group of elements did Medeleev overlook until the early 1900’s

3. How did Mendeleev organize the periodic table?

4. Above what atomic number do elements not exist naturally? [pic]

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