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 13-18 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 O2 & O3.
Element song
• SpongeBob sings it!• So do the Chipmunks!
Cooperative GroupsTeam Alkali Metals
Anthony CDonald CNoah S
Team Alkaline Earth MetalsTatyana KIsaiah FBethany L
Team HalogensTyler HJadiAnn HJorge M
Team Noble GasesTim BAutumn SJaQuona R
Team Transition Metals
Metals, Metalloids & Nonmetals:
Metals, Metalloids & Nonmetals:
Property METAL SEMIMETAL NONMETAL 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
Property METAL SEMIMETAL NONMETAL 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 – I2Liquid – BrGas – N2, O2, F2, Cl2
Important examples:
Au, Ag, Fe, Ni, Cr, Na, K , Fr, Ca, Mg, Pt
Al, Si, Ge C, S, P, Br2, I2,N2, O2, F2, Cl2
Ionization EnergyElectronegativity
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 3Li, 9F, 87Fr
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 (IA) 2 (I IA) 13 (I I IA) 14(IVA) 15 (VA) 16 (VIA) 17 (VIIA) 18 (VII IA)
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 270X-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 1350X-axis : start at 0, count by 5, stop at 90
Reactivity of Metals Demo (pg 14)
You have learned that trends occur in the physical & chemical properties of elements both horizontally & vertically on the periodic table. In this lab demonstration you will observe trends down groups 1 & 2, and the trends across periods 3 & 4.
1 2 13 14 15 16 17 18IA IIA VIIIA
1 II IA IVA VA VIA VIIA2 F3 Na Mg 3 4 5 6 7 8 9 10 11 124 K Ca567 Fr
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.
Physical properties of group IA & IIA metals IA (1) IIA (2) Na
Mg
K
Ca
Observe the reactions of each metal as the instructor places it in water. Record your observations below.
Reactivity of group IA (1) & IIA (2) metals in water IA (1) IIA (2)
Na
Mg
K
Ca
Video demos of alkali metals
Video of sodium in waterVideo if potassium in waterVideo of Cesium in waterVideo 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 & electronegativitylose 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 & electronegativitylose 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: Fe Cr Ni Cu
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/ FBP increases with increasing size
Never found free in nature: groups 1, 2, 17Colored ions due to multiple oxidation states: transition metals