Periodic Patterns

The Periodic Table

Design of the Periodic Table Classification of Element By looking at where a element is on the periodic table, you can tell about it’s chemical and physical properties Columns (18) Up and down Called Families/Groups Elements in Families have similar properties Rows (7) Side to Side Called Periods Elements in periods DO NOT have similar properties

The first two and last six columns are numbered 1A-8A, relates to the # of electrons in their OUTER shell. 1A 2A 3A 4A 5A 6A 7A 8A

Properties of the metals These elements are metals: Physical Properties Luster- Shininess Ductile and malleable- able to be drawn into wires and hammered into sheets Chemical Properties Corrosive- wearing down due to chemical reaction Easily lose electrons

Alkali Metals Group 1 Very reactive Form +1 ions Cations Examples: H, Li, Na

Alkaline Earth Metals Group 2 Reactive Form 2+ ions Cations Examples: Be, Mg, Ca, etc

Transition Metals Groups 3B-12B on the Periodic Table Much less reactive than Alkali or Alkaline Earth Metals Only 1 that is a liquid at room temp Mercury – Hg Examples: Cr, Co, Ni, Fe, Cu, Ag, Au

Properties of non-metals These elements are non-metals: Physical Properties No Luster Not ductile or malleable Chemical Properties Tend to gain electrons

Nonmetals Not good conductors Found on right side of periodic table – AND hydrogen Usually brittle solids or gases

Halogens Group 17 Very reactive Form 1- ions Anions Examples: F, Cl, Br, etc

Properties of Noble Gases These Elements are Noble gases: Group 18 Unreactive, inert, “noble” Have a 0 charge, no ions Examples: He, Ne, Ar, Kr, etc

Properties of Metalloids These Elements are metalloids Form the “stairstep” between metals and nonmetals Properties Can have both of metals and non metals Sometimes called semiconductors Example: Can be shiny or dull, malleable or not…

Properties of rare Earth metals These Elements are rare Earth metals: Properties: The rare earths are silver, silvery-white, or gray metals. The metals have a high luster, but tarnish readily in air. The metals have high electrical conductivity. Lanthanides - part of period 6 Actinides - part of period 7

Atoms Inside the Atom Elements are made of particles called atoms Atoms are the smallest pieces of matter that contain all the properties of a specific element Each element contains only one type of atom Inside the Atom Atoms are made up of smaller particles These particles are found in different regions of the atom

Neutron Protons Electron Neutral particles found in nucleus of atom Positively charged particles found in nucleus of atom Have an electrical charge of +1 Mass of 1 a.m.u. Neutron Neutral particles found in nucleus of atom Have no electrical charge Electron Negatively charged particles found in electron cloud Have an electrical charge of -1 Constantly moving around outside nucleus Have essentially no mass

Structure of the Periodic Table Atomic number – Tells us how many protons and electrons are in an atom The number of protons defines the identity of the atom Atomic Mass – gives the mass of a single atom in atomic mass units (amu) Atomic mass = # p+ + n0 Oxidation Number – tells us what the atom wants to do with electrons

Structure of the Periodic Table The Periodic Table also tells us about the electron structure of an atom Each Period represents an energy level in the electron cloud Ex: Na is in the 3rd Period, therefore its electron cloud will consist of 3 Energy levels The Group number represents the number of electrons in the outer energy level Ex: Na is in a Group 1 element, therefore it has one electron in the outer energy level The number of boxes in each period indicate the number of electrons that the energy level can hold

Comprehension Check How many energy levels does aluminum’s electron cloud have? 3 How many electrons are in aluminum’s 2nd energy level? 8 How many electrons are in aluminum’s 3rd energy level?

Symbols Elements are listed by their chemical symbols Symbols are usually either one capital letter like C for Carbon, or one capital and one lowercase letter like Ne for Neon

Periodic Table The periodic table gives much information we need to learn more about the atom of each element

Atomic Mass Mass # = # p+ + # n0 The average atomic mass is the number at the bottom of this square Found by averaging the natural abundances of its isotopes Mass # = # p+ + # n0

Atom Math Atomic Number Symbol Element Name Atomic Mass

Atom Math Protons Electrons Protons Neutrons

Practice # n0 = Mass # - Atomic # Zn Oxygen Lithium 8 30 3 15.999 65.39 6.941 8 30 3 35 8 4 8 30 3 # n0 = Mass # - Atomic #

Mass # Atomic # Isotopes Nuclear symbol: Hyphen notation: carbon-12 Atoms of the same element with different mass numbers. Nuclear symbol: Mass # Atomic # Hyphen notation: carbon-12

Isotopes © Addison-Wesley Publishing Company, Inc.

How many eggs go in an egg carton?

The Role of Electrons in Bonding The sharing or transfer of electrons is what holds atoms together in a compound Typically, only the electrons in the outer energy level are used for bonding. These electrons are called Valence Electrons The outer energy level is called the Valence Shell Octet Rule: atoms want to have a full valence shell (8 valence electrons) Atoms react with one another in an attempt to gain or lose electrons to fill their valence shell During a reaction, electrons can be shared or completely transferred

Comprehension Check How many valence electrons does phosphorus have? 5 How many electrons does phosphorus have to gain or lose in order to fill its valence shell? Lose 5, Gain 3

Comprehension Check- To Gain or Not to Gain nitrogen beryllium xenon carbon Gain 3 Lose 2 None Gain/Lose 4 oxygen lithium chlorine boron Gain 2 Lose 1 Gain 1 Lose 3

Types of Bonds Ionic Bonds – Results from the complete transfer of electrons Results in a formation of two charged atoms called ions The atom that gains electrons becomes negatively charged and is called an anion The atom that loses electrons becomes positively charged and is called a cation The attraction of the positive and negative charges results in a very weak bond Covalent Bonds – Results from the sharing of electrons The shared electrons create a very strong bond These are the bonds that make molecules possible

Oxidation Numbers Oxidation Numbers tell us how many electrons an atom is willing to lose or gain Positive oxidation numbers indicate that the atom can lose that many electrons Negative oxidation numbers indicate that the atom can gain that many electrons Some atoms have more than one possibility