The Periodic Table

The Element Song

What is an element? All matter is made up of atoms, and each unique atom represents a different element.  Atom – The smallest unit of matter that can take part in a chemical change and keep its characteristics. A pure substance that cannot be broken down into simpler substances.  Elements are made up of identical atoms.

Subatomic Particles Subatomic Particle  A particle smaller than an atom.  Electrons, Neutrons and Protons

Today’s Atom – The Periodic Table Chemical symbol  An abbreviation of the name of an element.  E.g. Carbon = C Helium = He There are 2 rules for finding the symbol for an element:  A single-letter symbol is always capitalized  E.g. Oxygen = O  The first letter of a two-letter symbol is always capitalized.  E.g. Lithium = Li

The Periodic Table Period:  the horizontal rows of the periodic table.  Numbered 1-7  Indicates the number of electron shells or orbitals. Group/Family:  The vertical columns of the periodic table.  Contain elements with similar properties  They all have the same number of outer shell electrons called : VALENCE ELECTRONS

Alkali Metals Hydrogen is an exception. It is an explosive gas but is placed in the Alkali metals because it only has 1 electron. Alkaline Earth Metals Transitional Metals Staircase = Metalloids Chalcogens Halogens Noble Gases Metals: To the left of the staircase Non-Metals: To the right of the staircase

The Main families/Groups Group IA: Alkali Metals Group IIA: Alkaline Earth Metals Group VIA: Chalcogens Group VIIA: Halogens Group VIIIA: Noble Gases Note: Hydrogen is a family all to itself.

The Periodic Table There are 3 main types of elements on the periodic table:  Metals  Non-metals  Metalloids

Metals Most common form of matter 75% of the P.T. are metals On the left side of the “staircase” Lustre (shiny) Silver/Gold colour Malleable (flexible, bendable, flattened) Ductile (drawn into wires) Solid (Hg is liquid, H is a gas) Conducts heat and electricity

Non-Metals Located on the right side of the periodic table 15% of elements are non-metals Opposite of metals No lustre Brittle (breaks) Does not conduct heat or electricity well Insulators Solids, some gas, liquids

Metalloids Surrounds the stair case 6-10% of elements on the P.T. Some properties of metals but not all. Solid at room temp. Some have lustre Semi-Conductors

Hindenburg May 6, 1937, the Hindenburg carrying 61 crew and 36 passengers took flight. This 804-foot dirigible filled with over 7 million cubic feet of hydrogen was a crowning achievement of its age. Never before or since has a larger aircraft taken flight. Many theories were talked about and investigated: sabotage, mechanical failure, hydrogen explosions, lightning or even the possibility that it was shot from the sky.

The Elements Element kit How small is an atom?  Alkali metals in water!  

How to read the periodic table Jersey analogy  Noble Gases = Team Name  Atomic # 36 = Player #  Symbol Kr = Mascot  Krypton = Player Name  Mass = Stats Noble Gases

Bohr Diagrams Protons and Neutrons are found within the nucleus. Electrons travel around the nucleus in specific paths called orbits or shells.  These shells exist whether they are occupied or not.

The Rule 1 st shell – holds a max of 2 electrons 2 nd shell – holds a max of 8 electrons 3 rd shell – holds a max of 8 electrons

How do you find the number of Protons and Electrons? Each element has a unique atomic number that identifies how many protons are in one atom of that element.  The Atomic number = the number of protons Atoms must have equal numbers of protons and electrons. Therefore:  The Atomic number also = the number of electrons E.g. Calcium has 20 protons AND 20 electrons “P.E.A rule” = # of protons = # of electrons = atomic number

How do you find the number of Neutrons? You simply take the "Atomic Mass" (the larger number), round the atomic mass to a whole number to get the Mass Number, and subtract the Atomic Number from it.  # Neutrons = Mass Number - Atomic Number Example: Hydrogen (H)  atomic number = 1  number of protons = 1, and number of electrons = 1  atomic mass = which rounds to 1  #of neutrons = atomic mass – atomic number = 1-1 = 0

Summary Table Subatomic Particle Symbol and Charge MassLocation Protonp+1 amuNucleus Neutronn1 amuNucleus Electrone-1/1837 amuElectron shells Note: AMU = Atomic Mass Unit

Atomic Symbols Note that the mass number may be on the top or bottom (the mass number is always the larger of the two)

To Draw Bohr Diagrams 1. Draw the nucleus as a solid circle. 2. Put the number of protons (atomic number) in the nucleus with the number of neutrons (atomic mass – atomic number) under it. 3. Place the number of electrons (same as protons) in orbits around the nucleus by drawing circles around the nucleus. Remember the Rule: Remember the Rule:1 st shell – 2 electrons 2 nd shell – 8 electrons 3 rd shell – 8 electrons

# of protons in the atom # of Electrons in the atom # of neutrons in the atom Atomic mass of the atom Atomic # of the atom Element name Chemical symbol NitrogenN BoronB HydrogenH CalciumCa ZincZn AluminumAl FluorineF VanadiumV ChlorineCl LithiumLi GoldAu SodiumNa ArsenicAs TinSn PotassiumK

Elemental Symbols Most elemental symbols are based off the name of the element. Some derive their name from other sources:  Gold = Au (Latin name aurum)  Silver = Ag (Latin name argentum)  Lead = Pb (Latin name plumbum)  Tungsten = W (from the German Wolfram)