Unit 3 Periodic Table

Robert Boyle The first scientist to be concerned with careful measurements The first scientist to be concerned with careful measurements Did not hold any assumptions as to how many elements there were Did not hold any assumptions as to how many elements there were Decided that only experimentation would tell Decided that only experimentation would tell

Element 101 Basic building blocks Basic building blocks 1 atom or many atoms of the same kind = an element 1 atom or many atoms of the same kind = an element Presently there are about 120 elements Presently there are about 120 elements 88 occur naturally 88 occur naturally The 9 most abundant make up 98% of the earth’s mass The 9 most abundant make up 98% of the earth’s mass Oxygen 49% Oxygen 49% Silicon 25 % Silicon 25 % Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium, and Hydrogen Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium, and Hydrogen Diatomic molecules are ELEMENTS! Diatomic molecules are ELEMENTS! Two atoms of the same element bonded together… know them! Two atoms of the same element bonded together… know them!

Mendeleev's Periodic Table: The first one! - Can you see any patterns? - How was it arranged?

Build Your Own Table Time!! - In groups of 2-3 you will be building your own tables - Be sure to write down information that will help you organize this again!

What’s on the table? Atomic number Atomic number Number of protons Number of protons Defines the element Defines the element Atomic Mass Atomic Mass The average mass of all the isotopes of that element The average mass of all the isotopes of that element Atomic Symbol Atomic Symbol Name Name Mass Number Mass Number The mass of a single isotope of an element The mass of a single isotope of an element

Color Time!!!!!

Elemental Nomenclature Elemental name are often derived from Latin or Greek words Elemental name are often derived from Latin or Greek words Aurum – shining dawn Aurum – shining dawn Plumbum – heavy Plumbum – heavy Bromus - stench Bromus - stench

26 Common Elements and Their Symbols… You MUST know these!

Atomic Anatomy - Proton - p+ - Nucleus - 1 AMU - Electron - e- - Electron cloud - 1/1847 AMU - Neutron - n - Nucleus - 1 AMU

Using Your Table Calculating Protons: - Atomic number - Same as electrons in neutral atoms Calculating Electrons: - Same as protons in neutral atoms Calculating Neutrons: - M# - A# = # of neutrons - DO NOT USE atomic mass, must use mass #

Element Quiz Provide the symbol for the following elements: 1.Aluminum 2.Bromine 3.Potassium 4.Sodium 5.Lead 6.Copper 7.Nitrogen 8.Zinc Provide the name for the following symbols: 9. Mg 10. Ag 11. Cr 12. I 13. Sn 14. F 15. S 16. Hg Spelling Does Count!

Atomic Structure Quiz Provide the following 5 pieces of information for the given atoms: #p +, #n 0, #e -, mass #, atomic # LOOK AT THE CHALKBOARD!

Isotopes and the Nucleus Isotopes are atoms with the same number of protons, but different numbers of neutrons. Do they have the same mass? Are they the same element?

How many protons? How many neutrons? -Isotopes are described by their mass number -Examples: -C-12 and C-14

Isotope Math Calculating Mass # #n 0 + #p + = mass # Calculating Average Mass of given isotopes (sum of mass #s)/(# of atoms) = Ave Mass Calculating Weighted Masses (by percent) (%A)(Mass #A) + (%B)(Mass #B) + …= Weighted Mass

Try Some!! Calculate Average Mass 1 atom has a mass of 10 1 atom has a mass of 12 1 atom has a mass of 8 30/3=10 AMU 5 atoms have a mass of 10 each 17 atoms have a mass of 12 each 3 atoms have a mass of 8 each 278/25 = 11.1 AMU 5 x 10 = x 12 = x 8 = 24 = 278

One more! 39% have a mass of 10 AMU 39% have a mass of 10 AMU 11% have a mass of 12 AMU 11% have a mass of 12 AMU 50% have a mass of 8 AMU 50% have a mass of 8 AMU Total Total = 9.22 AMU = 9.22 AMU Isotopes of B WS

From the Nucleus to the Cloud Electrons are negatively charged Electrons are virtually massless Electrons are FAST! Electrons are quantized Electrons inhabit orbitals (aka rings or shells)

Outer Atomic Structure - - Electrons “live” outside the nucleus - - Electron Shells (Bohr) - - Electron Cloud (Schrodinger) - - The outermost electrons are valence electrons - - All other electrons are core electrons Core e- = (Atomic #) – (Valence e-)

The importance of valence electrons Valence electrons are on the outer shell Valence electrons are on the outer shell They are the electrons that are involved in reactions They are the electrons that are involved in reactions We can describe chemical behavior by knowing the number of valence electrons We can describe chemical behavior by knowing the number of valence electrons Perioic table and electrons… using your table again! Perioic table and electrons… using your table again!

Ions Ions are atoms that are no longer neutral, they have a charge Ions are atoms that are no longer neutral, they have a charge Electrons can be removed or added Electrons can be removed or added Removed = + Removed = + Added = - Added = - Ions are usually unstable and very reactive Ions are usually unstable and very reactive

The “address” for the electron in a neutral atom Ground State Electron Configurations

Electron Questions 1. What is the “address” for electrons in an atom? 2. How can we find the electron’s “address”

Valence shell Valence electrons Core electrons GroupsPeriodsShells Use the following terms in 2-4 sentences that describe how we can find the following on the periodic table. You may work with 1 partner.

Purple – The final electrons for these elements are in the “s” orbital Pale Yellow – The final electrons for these elements are in the “p” orbital Teal – The final electrons for these elements are in the “d” orbital Light Green – The final electrons for these elements are in the “f” orbital

Orbital Filling - Aufbau Principle -Electrons will fill the LOWEST energy levels first. -This is known as the Aufbau (building up) principle. -Electron filling follows the diagram “s” orbitals can hold up to 2 electrons “p” orbitals can hold up to 6 electrons “d” orbitals can hold up to 10 electrons “f” orbitals can hold up to 14 electrons NOTICE: Certain orbital types ONLY show up in certain shells The order ends up: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 2 5f 14 6d 10 7p 6

Electron Configurations and Dot Diagrams: Show the electron configuration and dot diagram for the following: LiO BeNe NaTi

Models of the Atom Solid Model (Dalton) Solid Model (Dalton) Plum Pudding Model (Thomson) Plum Pudding Model (Thomson) Rutherford Model Rutherford Model Bohr Model Bohr Model Cloud Model (Schrodinger) Cloud Model (Schrodinger)

Dalton’s Atomic Theory English Science teacher in the 1800’s English Science teacher in the 1800’s Offered a 5 part theory for the structure of an atom Offered a 5 part theory for the structure of an atom

Dalton’s Theory Elements are made up of small particles called atoms All atoms of a given element are identical The atoms of a given element are different from those of any other element Atoms of one element can combine with atoms from another element to form compounds. A given compound always has the same relative numbers and types of atoms Atoms are indivisible in chemical processes. That is, atoms are not created or destroyed in chemical reactions. A chemical reaction simply changes the way atoms are grouped together.

Plum Pudding Model Proposed by J.J. Thomson in the 1800’s Proposed by J.J. Thomson in the 1800’s First experimental proof of different charges in an atom First experimental proof of different charges in an atom Said the atom looked like “pudding with plums in it” Said the atom looked like “pudding with plums in it” Plums were the evenly distributed positive and negative charges. Plums were the evenly distributed positive and negative charges.

Rutherford’s Model Proof of a solid nucleus Proof of a solid nucleus Most particles moved through the foil untouched Most particles moved through the foil untouched Foil was mostly empty space Foil was mostly empty space Some particles were deflected Some particles were deflected There must be a solid, dense nucleus with a positive charge There must be a solid, dense nucleus with a positive charge

Niels Bohr’s Model of the Atom Based on data obtained from the atomic spectrum Based on data obtained from the atomic spectrum Electrons must be “quantized” Electrons must be “quantized” Only inhabit specific levels of energy (quanta, orbitals) Only inhabit specific levels of energy (quanta, orbitals) Must be several levels Must be several levels Atoms can jump from one level to another, but cannot inhabit in between levels Atoms can jump from one level to another, but cannot inhabit in between levels Incorporated ideas from Quantum Physics Incorporated ideas from Quantum Physics

Bright Line Spectrum of Hydrogen

Schrodinger’s Cloud Model Schrodinger was a physicist Schrodinger was a physicist Calculated the probability of an electron being in each level Calculated the probability of an electron being in each level Plotted the probabilities and determined a function to calculate the position or energy of an electron Plotted the probabilities and determined a function to calculate the position or energy of an electron This is the model most scientists refer to today This is the model most scientists refer to today