Chemistry Topic 5

The Periodic Table

• 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

Periodic Trends

Reactivity of elements

• Groups 1, 2, and 17 are usually only found in compounds

• They can be obtained by the electrolysis of their salts

Hydrogen

• Often loses its electron and forms H+

• Combines with metals to form hydrides H-

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

• 11/25 Chemistry • The Periodic Table • Aim: How can we demonstrate our knowledge of

Chemistry? • Obj: SWBAT answer Regents questions • Do Now: Clear Desk • REMEMBER: If you have an IEP that allows for

extra time and you would like to take that time, just let me know at the end of the period