chemistry topic 5starec.enschool.org/ourpages/auto/2016/9/15... · •create a picture of an atom...
TRANSCRIPT
• 11/16 Chemistry • The Periodic Table • Aim: How’s the Periodic Table arranged? • Obj: SWBAT explain the organization of the
Periodic Table • Do Now: If you were organizing the elements,
how would you do it? • HW: Memorize elements 1-20 name and symbol
Periodic Table • Arranged in order of INCREASING ATOMIC
NUMBER
• “properties of the elements are periodic functions of their atomic numbers”
• Periods = Horizontal Rows
– Number at the beginning of the period is the number of energy level
– Valence electrons increase from left to right
Going Across Periods • Metals (~75% of all elements)
• Metalloids (have properties of both metals and nonmetals)
• Nonmetals
• Ends with a NOBLE GAS
• Groups / Families = Vertical Columns
• Elements have the same number of valence electrons (last # in electron configuration)
• Elements in same group have similar CHEMICAL PROPERITES
Metals
• Most active are Groups 1 and 2
• Solids at room temperature (except Mercury (Hg) which is a liquid)
• 11/17 Chemistry • The Periodic Table • Aim: What are some properties of the elements? • Obj: SWBAT describe different characteristics of
the elements • Do Now: Describe in both terms of electron
configuration and position on the periodic table why F and Br are chemically similar
• HW: Memorize elements 21-40 name and symbol
Properties of Metals
• Malleable = can be hammered into shape
• Ductile = can be drawn or pulled into a wire
• Have luster = shiny
• Good conductors of heat and electricity
• Low ionization energy
• Tend to lose electrons and form positive ions with smaller radii
Transition Elements / Transition Metals
• Characterized by multiple oxidation states
• Often form ions that have color.
Metalloids
• AKA semimetals
• B, Si, Ge, As, Sb, and Te
• Display both metallic and nonmetallic properties
Nonmetals
• Most are gasses at room temperature (except Bromine (Br) which is a liquid)
• Brittle
• Dull
• High ionization energy and high electronegativity
• Poor conductors
• Tend to gain electrons to become negative ions with larger radii
Noble Gases • Group 18
• NONREACTIVE
• Completely filled outer energy level of electrons
• Helium has 2 electrons. All other noble gases have a complete OCTET (8 electrons)!!!
Allotropes • When nonmetals exist in 2 or more forms in
the same phase
• They have different physical and chemical properties!
• Ex. O2 and O3 (oxygen gas and ozone)
• Carbon = graphite (stuff in pencils), diamonds, and buckministerfullerene
• 11/18 Chemistry
• The Periodic Table
• Aim: What trends can be found in the Periodic Table?
• Obj: SWBAT analyze the reason behind these trends
• Do Now: Describe in both terms of electron configuration and position on the periodic table why Na and Li are chemically similar
• HW: Finish Packet
Ionization Energy
• Energy needed to remove an electron
• Increases across period
• Decreases down group
Why
• Across period you are adding protons but keeping the number of electron shells the same so the protons pull on the electrons more strongly, making them harder to remove
• Down group you’re adding electron shells, pushing them further away from the nucleus making them easier to remove.
– Also inner electron shells “shield” the outer ones
Atomic Radius
• Half the distance between two adjacent atoms in a crystal or half the distance between nuclei of identical atoms that are bonded together.
• Decreases across period
• Increases down group
Why
• Across period you are adding protons while keeping the number of electron shells the same, which pull the electrons more strongly, causing them to move more inward.
• Down a group you’re adding electron shells which causes the radius to be larger.
Ionic Radius
• Metals lose electrons and become smaller positive ions
• Nonmetals gain electrons and become larger negative ions.
Electronegativity
• An atom’s attraction to electrons when bonded
• Fluorine is highest at 4.0
• Closer to F is higher
• Increases across period
• Decreases down group
Reactivity of elements
• Groups 1, 2, and 17 are usually only found in compounds
• They can be obtained by the electrolysis of their salts
Group 1 and 2
• Group 1 = Alkali Metals
• Group 2 = Alkaline Earth Metals
• Lose electron(s)
• Reactivity increases
going down group
• Group 1 is more
reactive than Group 2
Fun Facts the Regents LOVES asking about
• Nitrogen is a diatomic molecule with a triple covalent bond
• Oxygen is a diatomic molecule with a double covalent bond
• (I will prove these to you next unit) – You don’t need to write down that part though…
• I wonder who actually wrote it without reading ahead.. – If you did don’t say anything, I want to see how far people will
go for
» PLEASE FOR THE LOVE OF SCIENCE STOP COPYING THIS!
Group 17
• Halogens
• Lose electron and form 1- ions
• Contains all 3 states of matter (Bromine is a liquid)
• Very high electronegativities and reactivity
Group 18
• Noble Gases or Inert Gases (don’t react)
• Filled valence shell nonreactive (except at high temperature and pressure)
• 11/19 Chemistry
• The Periodic Table
• Aim: How can we synthesize what we’ve learned about elements through creative works?
• Obj: SWBAT create artistic representations of atoms to better educate others
• Do Now: Describe in both terms of electron configuration and position on the periodic table why Ca and Mg are chemically similar
• HW: Finish Packet
• Create a picture of an atom of an element
• Include a key
• Include protons, neutrons, and electrons
• Show the atomic number and mass number of the atom
• List other characteristics (atomic radius, ionization energy, electronegativity, etc.)
• Make it aesthetically pleasing (they’re going to go in a bulletin board soon)
• 11/20 Chemistry
• The Periodic Table
• Aim: How can we illustrate our understanding of chemistry through differentiated tasks?
• Obj: SWBAT express their knowledge of chemistry through various means.
• Do Now: Describe in both terms of electron configuration and position on the periodic table why Ne and Ar are chemically similar
• HW: Finish Packet
• 11/23 Chemistry • The Periodic Table • Aim: How can we prepare for our exam? • Obj: SWBAT answer questions to prepare for their
exam. • Do Now: Describe in both terms of electron
configuration and position on the periodic table why O and S are chemically similar
• HW: Study
• 11/24 Chemistry • The Periodic Table • Aim: How can we prepare for our exam? • Obj: SWBAT solve riddles to enhance their
understanding of Chemistry • Do Now: Describe in both terms of electron
configuration and position on the periodic table why Ag and Au are chemically similar
• HW: Study