Learning objectives: After completing this unit of study, you should be able to: An element’s location on the periodic table gives an indication of its physical and chemical properties. Elements on the Periodic Table are arranged in order of increasing atomic number. Elements are classified as metals, nonmetals and metalloids based on their properties and location on the periodic table. Groups 1, 2, and have the same number of valence electrons in the group, and therefore have similar chemical properties. Helium is the exception to this. Each group shows trends in atomic radius, ionic radius, Electronegativity, first ionization energy, and metallic and nonmetallic properties. Each period shows trends in atomic radius, Electronegativity, first ionization energy, and metallic and nonmetallic properties. When an element becomes an anion by gaining electrons, the radius increases. When an element becomes a cation by losing electrons, the radius decreases. Some elements exist as two or more forms in the same phase due to differences in molecular or crystal structures, and therefore have different chemical and physical properties. These are called Allotropes. Carbon has the allotropes coal, graphite, diamond, and fullerenes. Oxygen has the allotropes O 2 & O 3.

Element song SpongeBob sings it! SpongeBob So do the Chipmunks!Chipmunks

Cooperative Groups Team Alkali Metals Anthony C Donald C Noah S Team Alkaline Earth Metals Tatyana K Isaiah F Bethany L Team Halogens Tyler H JadiAnn H Jorge M Team Noble Gases Tim B Autumn S JaQuona R Team Transition Metals

Metals, Metalloids & Nonmetals:

PropertyMETALSEMIMETALNONMETAL LOCATION LUSTER – SHINY? CONDUCTIVE OF HEAT & ELECTRICITY? MALLEABLE – can bend without breaking? PHYSICAL STATE at RT? Important examples: GENERAL ATOMIC STRUCTURE TENDENCY TO LOSE OR TO GAIN ELECTRONS? # OF VALENCE ELECTRONS

PropertyMETALSEMIMETALNONMETAL LOCATION right & above staircase line bordering the staircase line left & below the staircase line LUSTER – SHINY? yes - luster maybe no - dull CONDUCTIVE OF HEAT & ELECTRICITY? yes maybe no MALLEABLE – can bend without breaking? yes – malleable & ductile maybe no- brittle & hard PHYSICAL STATE at RT? solids, Mercury (Hg) is only liquid metal solids Solids – I 2 Liquid – Br Gas – N 2, O 2, F 2, Cl 2 Important examples: Au, Ag, Fe, Ni, Cr, Na, K, Fr, Ca, Mg, Pt Al, Si, Ge C, S, P, Br 2, I2,N 2, O 2, F 2, Cl 2 Ionization Energy Electronegativity Lo IE & lo EN N/A Hi IE & Hi EN TENDENCY TO LOSE OR TO GAIN ELECTRONS? Lose, forming cations Gain or Lose Gain, Forming anions # OF VALENCE ELECTRONS 1-3 valence e- 3-5 val e- 5-7 val e-

Shielding Kernel electrons interfere with the nuclear attraction for valence electrons. More energy levels mean that it is easier to remove an e - and harder to gain an e -, because protons are shielded by the kernel e - in between them.

Nuclear Charge The charge of the nucleus The number of protons = atomic number Greater nuclear charge means greater attraction of nucleus on the electrons Means smaller radius, harder to lose e - (IE) easier to gain e - (e - neg)

Bohr models of 3 Li, 9 F, 87 Fr

Periodicity: FOLLOWS A PATTERN There are general trends in properties as you move left to right across a period. There are general trends in properties as you move top to bottom down a group.

Periodic Trend in Number of Valence Electrons

1.) What is the trend in valence electron number as you go from left to right across any period on the table? 2.) What is the trend in the valence electron number as you go down any group from top to bottom? 3.) What is the trend in the number of energy levels as you go down any group from top to bottom? 4.) Use your answers to #2 & 3 to write a statement explaining the relationship between number of valence electrons and the number of energy levels.

Chem Do 3 graph Y-axis: start at 50, increase by 10, stop at 220 X-axis : start at 10, count by.5, stop at 18

Chem Do 3b graphs “Trend in atomic radius down group 2” Y-axis: start at 100, increase by 10, stop at 270 X-axis : start at 0, count by 5, stop at 90 “Trend in ionization energy down group 1” Y-axis: start at 350, increase by 50, stop at 1350 X-axis : start at 0, count by 5, stop at 90

Reactivity of Metals Demo (pg 14)

Complete the following data table by making observations about the physical appearance of the metals shown by the instructor. Include luster(shine), hardness or softness, reaction with air.

Observe the reactions of each metal as the instructor places it in water. Record your observations below.

Video demos of alkali metals VideoVideo of sodium in water VideoVideo if potassium in water VideoVideo of Cesium in water Video Video of Francium in water

Groups/Families of the Periodic Table

Alkali Metals Location: group 1 Characteristic Elements: Na, K, Rb, Cs, Fr Reactivity: most active metals (Fr is THE most active metal), never found free in nature, electrolysis of fused salts. lo IE & electronegativity lose e-, IR<AR

Alkaline Earth Metals Location: group 2 Characteristic Elements: Be, Mg, Ca, Sr, Ba, Ra Reactivity: very hi, but less than group 1. Also never found free in nature, electrolysis of fused salts lo IE & electronegativity lose e-, IR<AR

Transition Metals Location: groups 3-12 Characteristic Elements: Fe, Cu, Cr, Au, Ag, Pt, Pb, Mn, Co… Special Characteristics: hard solids with hi MP, less reactive than groups 1 & 2 multiple oxidation states due to more than one energy level being filled at a time colored solutions in water

Why do transition metals produce colored solutions? MULTIPLE OXIDATION STATES! Look at: FeCrNiCu

Halogens Location: group 17 Characteristic Elements: F, Cl, Br, I, AS Reactivity: most reactive NONMETALS, Also never found free in nature, electrolysis of fused salts or chemically hi IE & electronegativity (F is highest of 4.0) gain e-, IR>AR Exhibit all 3 states of matter (F & Cl (g), Br (l), I & As (s))

Noble Gases Location: group 18 Characteristic Elements: He, Ne, Ar, Kr, Xe, Rn Reactivity: monatomic because full valence shell of 8 e- (He is full w/ 2 e-) therefore, do not react exception: Xe & Ar w/ F BP increases with increasing size

Never found free in nature: groups 1, 2, 17 Colored ions due to multiple oxidation states: transition metals