Mr. Mellon Regents Chemistry Unit 3: Periodic Table Have your Periodic Table out everyday for this unit Mr. Mellon Regents Chemistry

I. Historical Development of the Table A. Dmitri Mendeleev (__________) Arranged elements into table based on… similarities in the physical and chemical properties thought similarities were function of atomic mass Noticed that some elements seemed out of order (Iodine and Tellurium) Mendeleev Video Clip

I. Historical Development of the Table 1913 A. Henry Mosely (__________) Established that properties of elements were functions of ____________ Atomic Number 1. Present table based on ________________ Atomic Number 2. Elements’ properties depend on ________________ Structure of atom 3. Properties of elements vary ________________ Systematically throughout the table

II. Period (or Rows) Horizontal rows Number at the beginning of the period indicates the principle energy level in which valence electrons are located 1 PEL 2 PEL 3 PEL Periods 

II. Period (or Rows) 4 4 4 Not similar Example: A) What period is potassium and bromine in? ____ B) Based on the period, how many principal energy levels do potassium and bromine have? _______________ ____________________________________________ A) What period is potassium and bromine in? ______ B) Based on the period, how do the properties of potassium and bromine compare? _______________ 4 4 Properties change as you move across a period 4 Not similar

III. Groups(or Families) Vertical Columns Each group has similar chemical properties Because each group has same number of valence e- (except groups 3-12) # of valence e- 1 2 3 4 5 6 7 8 Groups

II. Period (or Rows) 2 Similar (both have 2 valence e-) Example: A) What group is magnesium and calcium in? ____ B) Based on the group, how do the properties of magnesium and calcium compare? _______________ 2 Similar (both have 2 valence e-)

III. Groups(or Families) Sample Questions: Which sequence of atomic numbers represents elements which have similar chemical properties? A) 19, 23, 30, 36 C) 9, 16, 33, 50 B) 3, 12, 21, 40 D) 4, 12, 38, 88   Which two elements have the most similar chemical properties? A) Aluminum and Barium C) Nickel and Phosphorous B) Chlorine and Sulfur D) Sodium and Potassium

IV. Metals Atoms that lose e- and form positive ions (cations) when bonding Alloy: Mixture of metals by melting them together

IV. Metals 1. Low ionization energy and electronegativity Properties of Metals: 1. Low ionization energy and electronegativity 2. Good conductors of heat and electricity 3. Exhibit metallic luster (shine) 4. Malleability (can be pounded into thin sheets) 5. Ductility (can be pulled into thin wires) 6. More than 2/3 of the elements are metals 7. High densities 8. Mercury (Hg) is a metal which a liquid at room temperature 9. Most active metal (bottom left corner): ________ Fr (Francium)

CHECKS FOR UNDERSTANDING IV. Metals CHECKS FOR UNDERSTANDING Which element is malleable and can conduct electricity in the solid phase? A) Iodine B) Phosphorous C) Sulfur D) Tin What happens to metals when they bond? What would happen to their atomic size? Where are the most reactive metals located? What about their atomic structure that makes them so reactive? Lose electrons; become smaller Bottom left corner; the electrons are far away (big atomic radius), so electrons can be easily removed (low ionization energy/electronegativity)

V. Nonmetals atoms gain e- and form negative ions (anions) when bonding

V. Nonmetals 1. High ionization energy and electronegativity Properties of Nonmetals: 1. High ionization energy and electronegativity 2. Poor conductors of heat and electricity 3. Brittle and hard 4. Low densities F (Fluorine) (top right corner) 5. Most active nonmetal: ________ Graphite is an allotrope of carbon. It is used in pencils (brittle, soft, and low density)

CHECKS FOR UNDERSTANDING V. Nonmetals CHECKS FOR UNDERSTANDING Which element is brittle and not a conductor of electricity? A) Sulfur B) Sodium C) Potassium D) Argon What happens to nonmetals when the bond? What happens to their atomic radius when they bond? Where are the most reactive nonmetals located? What about their atomic structure that makes them so reactive? Gain electrons; become larger Top Right corner (Group 17); small atomic radius so they attract electrons (High electronegativity/ ionization energy

VI. Metalloids Atoms that gain or lose e- and form ions when bonding Have properties of both metals and nonmetals Can be located using the “staircase” (see periodic table) Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium

CHECKS FOR UNDERSTANDING VI. Metalloids CHECKS FOR UNDERSTANDING Which element has both metallic and nonmetallic properties? A) Rb B) Rn C) Si D) Sr Which list of elements contains 2 metalloids? Si, Ge, Po, Pb C) As, Bi, Br, Kr Si, P, S, Cl D) Po, Sb, I, Xe

VII. Periodic Properties A. Covalent Atomic Radius: ½ of the distance between adjacent nuclei of the element

VII. Periodic Properties Periodic Trend (See Ref Tabs – Table _____) decreases Covalent Atomic Radius ___________ as you move from ______________________________ Left to right across a period PEL remains the same and outer e- get pulled closer to the nucleus increases Covalent Atomic Radius ___________ as you move from ______________________________ down a group # of energy levels increase

VII. Periodic Properties B. Ionic Radius: A loss or gain of e- causes an increase or reduction in atom’s size cations Metals: __________ electrons when they form ions ( _____________ ) and ionic radius __________ than neutral atom lose smaller 2-8-1 2-8

VII. Periodic Properties B. Ionic Radius: Nonmetals: __________ electrons when they form ions ( __________ ) and ionic radius __________ than neutral atom anions gain bigger 2-8-7 2-8-8

IV. Periodic Properties Sample Questions: Which element has an atomic radius that is greater than its ionic radius? A) S C) F B) K D) O In period 4, the atom with the largest covalent radius is located in group… A) 1 C) 3 B) 13 D) 18

VII. Periodic Properties C. Ionization Energy: Amount of energy needed to remove the most loosely bound e - (valence e -)

VII. Periodic Properties Periodic Trend (See Ref Tabs – Table _____) increases Ionization Energy ___________ as you move from ______________________________ Left to right across a period Number of protons and valence e- increases and size decreases, so e- are held tighter decreases Ionization Energy ___________ as you move from ______________________________ down a group e- are farther away, so easier to remove e- and valence e- are shielded by inner e-

VII. Periodic Properties D. Electronegativity: Measure of atom’s attraction for electrons when bonded Periodic Trend (See Reference Tables – Table _____): Electronegativity ______________ as you move from ______________________________ Electronegativity ______________ as you move from _____________________________ S increases Left to right across a period decreases down a group

IV. Periodic Properties Check for Understandings What are the electronegativities for group 18 elements? Why do you think they have “this” electronegativity? Which element attracts electrons the most when bonding? A) Ca C) Br B) Sr D) I Which element gives off its valence electrons the easiest? A) Ca C) Br B) Sr D) I They do not have electronegativity numbers. Why? Because they already have their 8 valence electrons (octet)

VIII. Groups within Groups Alkali Metals A. Group 1: ________________ All soluble (dissolves) in water and strongly basic Hydrogen is the exception on the periodic table – it belongs nowhere : ( Brainiac – Alkali Metals MYTHBUSTERS – ALKALI METALS Part 1 Part 2

VIII. Groups within Groups Alkaline Earth Metals B. Group 2: ______________________ Have 2 valence electrons Form +2 charge when they bond In General for Groups 1 and 2: As you move down, they become more reactive

VIII. Groups within Groups CHECKS FOR UNDERSTANDING As you move down groups 1 and 2 elements become more reactive. Explain why this happens based on atomic size and ionization energy/electronegativity. What will be the charge on a Ca ion when it bonds? Based on your answer to question 2, what happens to the atomic size once it becomes an ion? Size increases, ionization energy decreases (easier to remove e-) so they become more reactive +2 Smaller (loses last energy level)

VIII. Groups within Groups Transition Metals C. Groups 3-12: ________________ Dense Metals and high melting points Form multiple ions and less reactive than Groups 1 and 2 Form ions that have color

VIII. Groups within Groups CHECKS FOR UNDERSTANDING 4. Identify the metal that has multiple oxidation states. A) K B) Ba C) Be D) Pd 5. Which compound forms a green aqueous solution? A) RbCl B) CaCl2 C) NiCl2 D) BeCl2 6. Which set of properties is most characteristic of transition elements? Colorless ions in solutions, multiple positive oxidation states Colorless ions in solutions, multiple negative oxidation states Colored ions in solutions, multiple negative oxidation states Colored ions in solutions, multiple positive oxidation states

VIII. Groups within Groups Halogens D. Group 17: ________________ Have 7 valence e-, become -1 charge ion Mostly nonmetallic elements

VIII. Groups within Groups Noble Gases E. Group 18: ________________ All energy levels are full (2 or 8 valence electrons) Do not combine with other elements to form molecules (exist as monatomic in normal room conditions) They are stable All other elements want to be like them

VIII. Groups within Groups CHECKS FOR UNDERSTANDING Which halogen is most reactive? Explain why, based on atomic size, electronegative/ionization energy. Explain why noble gases don’t typically react with other elements? F: smallest in size so attraction for electrons is very high (electronegativity) Their outer energy level is completely full. They do not want to gain anymore e-

IX. Phases of Matter All of the information on the Periodic Table is given at STP STP - Standard Temperature and Pressure ( 0oC and 1 atm/101.3 kPa (sea level pressure)) Gases - H, N, O, F, Cl and Noble Gases Liquids - Br, Hg Solids - Everything else

X. Other Categories Diatomics - Molecule containing 2 identical atoms Remember them: H, O, F, Br, I, N, Cl (7-H club) Radioactive - An element that ALL its isotopes are unstable and break down spontaneously Remember them: Atomic # greater than 84 and 43 (Technitium), 61 (Promethium)

X. Other Categories Synthetic - Man-made elements (all are radioactive as well) Remember them: Atomic # greater than 93 and 43 (Technitium), 61 (Promethium)

X. Other Categories Allotropes- 2 or more different structural forms of an element in the same phase Remember them: Examples: C (s) – Diamond, graphite, coal, and Buckminster O (g) – O2 – Dioxygen- what we breath - O3 – Ozone - Toxic Diamond Graphite Coal Buckminster

X. Other Categories Allotropes- 2 or more different structural forms of an element in the same phase Remember them: Examples: O (g) – Diamond, graphite, coal, and Buckminster Diamond Graphite Coal Buckminster