Announcement Homework is due at the beginning of class. Put it on your desk during the first two minutes. HW detentions emailed at the beginning of class. You will need a “homework detention rescinding form” signed (after class!) if you didn’t complete your HW by the first two minutes of class.

Review Review subatomic particles, mass number, atomic number, average atomic mass

The Periodic Table of the Elements

Dmitri Mendeleev (1869) Organized the elements by atomic mass and other properties Looked for repeating patterns When arranged by increasing atomic mass, similarities in chemical properties appeared at regular intervals. Periodic: things that repeat at regular intervals

The Periodic Table is Born Mendeleev then created a table where elements with similar properties were grouped together: the first periodic table of the elements (1869)

The First Periodic Table

Atomic mass Always increasing? Empty spaces Predicted they would be filled by elements with certain properties By 1886 these spaces were filled, by elements with those properties!

Another Contribution Henry Moseley arranged elements by their atomic number, not by atomic mass Periodic Law: the physical and chemical properties of the elements are periodic functions of their atomic numbers Periodic functions: repeating patterns Related to the number and location of electrons

Increasing Atomic Number (and, more or less, atomic mass)

Periods (across rows) Groups (down columns)

Group Numbers 1 18 2 13 14 15 16 17

Elements in the same group have similar chemical and physical properties.

Areas of the PTE Non-metals Metals

A quick tour of the periodic table

Metals Solid at room temperature Conduct electricity Shiny Ductile and malleable: can be made into wires and beaten into sheets

Group 1: Alkali Metals Extremely reactive Why? Don’t exist alone naturally

sodium potassium cesium (l) rubidium

http://video. google. com/videoplay http://video.google.com/videoplay?docid=-2134266654801392897&ei=59rqSt_wCNSclAfixvCdCQ&q=alkali+metals&hl=en#

Group 2: Alkaline Earth Metals Very reactive

Non-Metals Liquids or gases at room temperature Don’t conduct electricity

Group 17: Halogens Very reactive non-metals Need only one electron to fill valence shell All exist as diatomic molecules Cl2, Br2, I2 (all colored)

Halogens – colored diatomic molecules fluorine pale yellow gas chlorine yellow-green gas bromine red-brown liquid iodine black-purple liquid purple gas

Group 18: Noble Gases Not reactive Gases at room temperature Stable electron arrangement

The Giant Periodic Table Project 6 C 12.01

The Giant Periodic Table Project Be neat Be bold! We need to be able to read this from anywhere in the room! Be creative, but not cluttered. Be accurate. Atomic mass to TWO digits (Ex: 12.01) is ideal.

Electron Configuration The arrangement of electrons in an atom Each element’s atoms are different How do we figure out what the electron configuration looks like?

So where are the electrons? Electrons do NOT orbit like planets.

Energy Levels Major shells (layers) around the nucleus lower levels filled before higher levels are filled 1st: 2 electrons 2nd: 8 electrons 3rd: 8 electrons

Practice with Simple Electronic Structure He B Mg Li Be O Ne Cl

Electron Apartment Building

Electronic Structure Energy levels Sub-levels Orbital Two electrons per orbital

Inside energy levels… Each energy level has one or more sub-level made from different shaped orbitals. Energy Level Number of Sub-levels 1 1 (s) 2 2 (s, p) 3 3 (s, p, d) 4 4 (s, p, d, f)

Sub-levels are made up of one or more orbitals

What is an orbital? Orbital: An area where you expect to find the electron.

Sub-levels Different shapes s – sphere one orbital p – figure eight three orbitals d – five orbitals f – seven orbitals

p Sub-level p sub-level has three orbitals px, py, pz

Energy Level Types of sub-levels Total orbitals 1 4 3 9 Electron capacity (orbitals x2) 1 s 2 s, p 1+3= 4 8 3 s, p, d 1+3+5= 9 18 s, p, d, f 1+3+5+7=16 32

How do we figure out where the electrons are? 1. Figure out the energy levels of the orbitals 2. Add electrons to the orbitals according to three rules Three Rules for Electron Configuration

1: Aufbau Principle An electron goes to the lowest-energy orbital that can take it.

2: Pauli Exclusion Principle No two electrons can have exactly the same configuration description Can have the same orbital, but must have opposite spins.

3. Hund’s Rule Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron All electrons that are by themselves in an orbit must have the same spin.

Energies of sub-levels

Multiple choice practice

Who arranged the periodic table by atomic number? Dmitri Mendeleev Henry Mosley Ernest Rutherford Democritus

Which property is not increasing from left to right on the periodic table? Atomic mass Atomic number Number of electrons Reactivity

Which is not a property of the metals? Shiny Gas at room temperature Conduct electricity Solid at room temperature

Which is a property of non-metals? Conduct electricity Gas or liquid at room temperature To the left of the staircase line Malleable and Ductile

Which is not a property of the alkali metals? Solid at room temperature Not reactive Extremely reactive Never exist alone in nature

Which accurately describes the maximum number of electrons in each energy level? 2, 8, 8 8, 8, 8 2, 2, 8 8, 2, 2

Which lists the sublevels in the correct order? d, p, s, f s, p, f, d p, s, f, d s, p, d, f

What is the name of the following orbital shape? d f

How many electrons can fit in the s sub-level/orbital? 1 2 3 Eight million

How many electrons can fit in any single orbital? 1 2 3 Eight million

How many electrons total can fit in the p sub-level? 2 4 6 14

How many d orbitals make up the d sub-level? 2 3 5 7

How many f orbitals make up the entire f sub-level? 2 3 5 7

How many electrons total can fit in the entire d sub-level? 2 6 10 14

Which rule states that the lower energy levels are filled before the higher ones? Aufbau Principle Pauli Exclusion Principle Hund’s Rule

Which rule states that electrons are alone unless there is no space left, and then they can be with another electron? Aufbau Principle Pauli Exclusion Principle Hund’s Rule

Which rule states that no two electrons can have the same configuration (that is, be in the same space at the same time)? Aufbau Principle Pauli Exclusion Principle Hund’s Rule

Take these notes on Orbital Notation paper

What do the orbitals/sub-levels "look like" when you put them all together?

1: Aufbau Principle An electron goes to the lowest-energy orbital that can take it.

2: Pauli Exclusion Principle No two electrons can have exactly the same configuration description Can have the same orbital, but must have opposite spins.

3. Hund’s Rule Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron All electrons that are by themselves in an orbit must have the same spin.

How do we write electron configurations? Orbital Notation Electron Configuration Notation Noble Gas Notation (shorthand) All ways to communicate where the electrons are in any atom.

s – sphere one orbital – 2 electrons p – figure eight three orbitals – 6 electrons d – five orbitals – 10 electrons f – seven orbitals – 14 electrons

Orbital Notation Electron configuration goes below a line or box Arrows representing electrons go on the lines or in the boxes 1s 2s 2p 3s 3p 4s

Be, Si, Ne, Cl

Write the orbital notation Homework notebook! Ne Na S Zn I

Electron Configuration Notation Main energy level Sub-levelElectrons Carbon (6 electrons) 1s22s22p2 Aluminum (13 electrons) 1s22s22p63s23p1 Oxygen Argon Copper Zirconium

Noble Gas Notation (Shorthand) Noble gasses have totally filled outer orbitals. If Ne (a noble gas) is 1s22s22p6, we can abbreviate Na (Sodium) as [Ne]3s1. Sodium has one more electron than Neon, so its Noble Gas Notation is Neon plus one electron in the s sublevel of the third energy level.

Practice Fe (Iron) Electron Configuration Notation Noble Gas Notation K (Potassium) Li (Lithium) Be (Beryllium)

Orbital Notation Boron 1s22s22p1 Atomic Number? How many electrons?

Aufbau Principle: start with 1s and work up in energy level Pauli Exclusion Principle: No two elements can have the same arrangement of electrons Hund’s Rule: Fill in one electron per orbital first, then go back.

s, p, d and f blocks of the periodic table

“Long form” periodic table groups periods

Electronic structures are related to the position of the elements on the periodic table s-block: s orbitals are filled p-block: p orbitals are filled etc.