Take a half sheet of paper and answer the following…. 1.What is located inside the nucleus of an atom? (protons, neutrons, or electrons) 2.What is found on the outside? 3.What is the atomic number equal to? 4.How do you calculate the number of neutrons there are in an atom? Periodic table popularity of the song

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Chemical Reactions Packet 2

Lewis Dot Structures Illustrates the number of valence electrons – Valence electrons = Number of electrons in outer shell – Placed around the symbol of the element Helps us determine how compounds are formed / how elements bond – The group # gives you the number of valence electrons

Valence electrons on the periodic table

Lewis Dot Structures

Steps to create Lewis Dot Structures

Practice Lewis Dot Diagram Practice ● Draw the Lewis Dot Diagram for Phosphorus ○ Phosphorus ○ Symbol: ____ ○ Atomic Number: _____ ○ Atomic Mass: ____ ○ Protons: ____ ○ Neutrons: _____ ○ Electrons: _____ ○ Valence Electrons: _______

Practice Answers Lewis Dot Diagram Practice ● Draw the Lewis Dot Diagram for Phosphorus ○ Phosphorus ○ Symbol: __P__ ○ Atomic Number: __15___ ○ Atomic Mass: _31___ ○ Protons: __15__ ○ Neutrons: __16___ ○ Electrons: __15___ ○ Valence Electrons: ___5____

Ionic Bonding Elements Goal = Stability – Elements want to be stable – In order to be stable they need to fill their outermost energy level completely “Complete its octet” (oct meaning 8) When outer level is filled – No Charge = Stable When outer level is not filled – Charge = Unstable

How do we figure out and elements charge? – Charge is determined by how many electrons they need to gain or lose to complete their outer level – Every element in the group has the same charge Example: All Halogens are -1

Practice Group Charge /

Types of bonds Ionic BondsCovalent Bonds Forms between a metal and a nonmetal. Forms between a nonmetal and a nonmetal Electrons are transferredElectrons are shared Strong BondsWeak bonds Hard / BrittleRelatively Soft Soluble in WaterInsoluble in water High melting and boiling pointsLow melting and boiling points Conducts electricityDoes not conduct electricity Solid at room temperatureLiquids and gases at room temperature

Ionic bonds Ionic Bonds – Bond in which one or more electrons from one atom are removed and attached to another atom. – It is when atoms transfer electrons One element gives electron One element takes electron

How does ionic bonding work? –Ionic Bonds occur between metals and nonmetals. –Opposite charges are going to attract –Their charges will cancel out and become 0 0 = Stable Example: = Does NOT equal 0 so you would need another -1 atom (of the same element)

How does the sharing work? – Na has the 1 lone electron to share in its outermost level – Cl needs 1 to complete its octet – Na will give 1 electron to Cl

Ionic Bonding Steps Step 1: Write charges to determine the number of atoms that are needed Step 2: Write Lewis dot diagrams with arrow showing electron movement Step 3: Write Final Compound

Ionic Bonding Problem: Sodium and Sulfur Step 1: Write charges to determine the number of atoms that are needed Step 2: Write Lewis dot diagrams with arrow showing electron movement Step 3: Write Final Compound =0

Naming Ionic Compounds (ADV. only) There are 3 ways to name ionic compounds We will focus on one way for a normal metal- nonmetal ionic compound. – Step 1- write down the name of the name of the name of the metal element. – Step 2- write down the name of the nonmetal – Step 3- remove the “-ine” at the end of the non- metal and replace with “-ide”

Bonding of atoms Why do atoms bond? – Each atom wants a full outermost energy level How do they do this? – By gaining/losing (ionic bond), or sharing (covalent bond) valence electrons to achieve the duet or octet rule aka: “being happy or stable” – Gives each atom an electron configuration similar to that of a noble gas Ex. Group 18: He, Ne, A

Types of bonds Ionic BondsCovalent Bonds Forms between a metal and a nonmetal. Forms between a nonmetal and a nonmetal Electrons are transferredElectrons are shared Strong BondsWeak bonds Hard / BrittleRelatively Soft Soluble in WaterInsoluble in water High melting and boiling pointsLow melting and boiling points Conducts electricityDoes not conduct electricity Solid at room temperatureLiquids and gases at room temperature

Covalent Bonds Definition A chemical bond in which two atoms share a pair of valence electrons Always formed between nonmetal and nonmetal. How to Draw Covalent Bonds Step 1: Draw the Lewis Dot structures and circle the electrons that are being shared Step 2: Redraw the bond using a line (it replaces the circle) Step 3: Write the final compound

Covalent Practice: Chlorine and Chlorine Step 1: Draw the Lewis Dot structures and circle the electrons that are being shared Step 2: Rewrite the elements with a line representing each shared pair (it replaces the circle) Step 3: Write the final compound

What is the difference between a molecule and a compound? – Molecule - When two or more atoms are joined together chemically Examples – Carbon Dioxide - CO 2 – Ozone - O 3 – Water - H 2 O – Compound - When two or more elements are joined together chemically Examples – Carbon Dioxide - CO 2 – Ozone cannot be an example because there aren’t two different elements – Water - H 2 O – All compound are molecules but not all molecules are compounds

Counting simple and complex molecules You write each element (elements only have one capital letter) and count how many of them there are C - 1 O - 1 H - 4 C - 6 O - 6 H - 12

Organic vs Inorganic Molecules (ADV only) Organic MoleculeInorganic Molecule Contain carbon and hydrogen bonds Can contain carbon OR hydrogen but NOT both Associated with living thingsAssociated with non-living things Examples include nucleic acids, fats, sugars, proteins, enzymes and hydrocarbon fuels. ● Table sugar or sucrose, C 12 H 22 O 11 ● Methane, CH 4 Examples include salts, metals, and substances made from single elements ● Table salt or sodium chloride, NaCl ● Carbon Dioxide, CO2 ● Diamond (pure carbon) ● Silver