Ms. Samayoa Chemistry Birmingham Community Charter High School Covalent Bonds Ms. Samayoa Chemistry Birmingham Community Charter High School Warm-Up Question: What makes an ionic bond?

Learning Objective and Vocabulary Learning Objective: Students will learn how to write covalent molecular compound names and formulas by completing a few problems through partner interaction. Academic Vocabulary Words: molecular compounds

REVIEW In the previous lesson, we learned about electrons being transferred (either elements lost electrons or elements gained electrons) This type of bond between a METAL and a NONMETAL is called an IONIC BOND, which results in a SALT being formed

COVALENT BONDS In this lesson, you will learn about another type of bond in which electrons are SHARED This type of bond is known as a COVALENT BOND A COVALENT BOND are atoms held together by SHARING electrons between NONMETALS

What is a covalent bond? A covalent bond is a bond between two NONMETALS Remind them of hydrogen

Check for Understanding Identify if the following compounds are covalent or ionic: CaO CO2 N2O3 MgO

Check for Understanding Identify if the following compounds are covalent or ionic: CaO – ionic CO2 – covalent N2O3 – covalent MgO – ionic

How to Name Covalent Bonds Element -ide Ending Fluorine (F) Fluoride Chlorine (Cl) Chloride Bromine (Br) Bromide Iodine (I) Iodide Oxygen (O) Oxide Sulfur (S) Sulfide Nitrogen (N) Nitride Phosphorous (P) Phosphide # Prefix 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- For the first element, start with the element name For the second element, start with the –ide name Use prefixes to show how many atoms of each type there are *DO NOT USE MONO- ON THE FIRST ELEMENT **IF YOU HAVE “AO” OR “OO,” TURN IT INTO “O.”

Naming Covalent Compounds - Example Element -ide Ending Fluorine (F) Fluoride Chlorine (Cl) Chloride Bromine (Br) Bromide Iodine (I) Iodide Oxygen (O) Oxide Sulfur (S) Sulfide Nitrogen (N) Nitride Phosphorous (P) Phosphide # Prefix 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- SF6 N2O5 N2O3 P4S10 CF4 Do it on the board

Naming Covalent Compounds - Example Element -ide Ending Fluorine (F) Fluoride Chlorine (Cl) Chloride Bromine (Br) Bromide Iodine (I) Iodide Oxygen (O) Oxide Sulfur (S) Sulfide Nitrogen (N) Nitride Phosphorous (P) Phosphide # Prefix 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- SF6 – sulfur hexafluoride N2O5 – dinitrogen pentoxide N2O3 – dinitrogen trioxide P4S10 – tetraphosphorous decasulfide CF4 – carbon tetrafluoride Do it on the board

Write the names for the following compounds Element -ide Ending Fluorine (F) Fluoride Chlorine (Cl) Chloride Bromine (Br) Bromide Iodine (I) Iodide Oxygen (O) Oxide Sulfur (S) Sulfide Nitrogen (N) Nitride Phosphorous (P) Phosphide # Prefix 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- P4S5 O2 SeF6 Si2Br6 SCl4 NF3

Write the names for the following compounds Element -ide Ending Fluorine (F) Fluoride Chlorine (Cl) Chloride Bromine (Br) Bromide Iodine (I) Iodide Oxygen (O) Oxide Sulfur (S) Sulfide Nitrogen (N) Nitride Phosphorous (P) Phosphide # Prefix 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- P4S5 – tetraphosphorous pentasulfide O2 – oxygen gas (dioxygen) SeF6 – selenium hexafluoride Si2Br6 – disilicon hexabromide SCl4 – silicon tetrachloride NF3 – nitrogen trifluoride

How to Write Covalent Molecular Formulas Element -ide Ending Fluorine (F) Fluoride Chlorine (Cl) Chloride Bromine (Br) Bromide Iodine (I) Iodide Oxygen (O) Oxide Sulfur (S) Sulfide Nitrogen (N) Nitride Phosphorous (P) Phosphide # Prefix 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- Look at the element names and write it down Look at the prefixes to learn how many atoms you have for each element

Write Molecular Formulas Example chlorine dioxide iodine pentafluoride dinitrogen trioxide phosphorus triiodide Do on the board

Write Molecular Formulas Example chlorine dioxide – ClO2 iodine pentafluoride – IF5 dinitrogen trioxide – N2O3 phosphorus triiodide – PI3 Do on the board

Practice Carbon tetrafluoride Silicon Dioxide Phosphorous mononitride Nitrogen trifluoride Boron trisulfide Carbon tetrachloride

Practice Carbon tetrafluoride – CF4 Silicon Dioxide – SO2 Phosphorous mononitride – PN Nitrogen trifluoride – NF3 Boron trisulfide –BS3 Carbon tetrachloride – CCl4

Covalent Bond and Lewis Dot Structures Ms. Samayoa Chemistry Birmingham Community Charter High School

Learning Objective and Vocabulary Learning Objective: Students will learn how to draw Lewis dot structures by drawing them for specific molecular compounds. Academic Vocabulary Words: Lewis Dot structures, molecular compounds, valence electrons

Review How can we figure out the number of valence electrons an element has by looking at the periodic table? Go over valence electrons and ionic charge on the periodic table

Lewis Dot Structures In order to further understand ionic and covalent bonds, we need to learn how to draw Lewis Dot structures

To do Lewis Dot Structure we first need to…. Understand what electronegativity is Electronegativity is….. As we go across the periodic table (the same period), electronegativity (increases or decreases)? As we go down a group, electronegativity (increases or decreases)?

Which element is more electronegative? Na or S K or Br Li or Rb F or Br

Which element is more electronegative? Na or S – because sulfur has more protons K or Br – because bromine has more protons Li or Rb – because lithium has less shells (less electron shielding) F or Br – because fluorine has less shells (less electron shielding)

Write the element in question and find out how many valence electrons it has Atomic Symbol # of valence electrons Oxygen O 6 Fluorine Nitrogen Sodium

Board Problem Examples: oxygen, fluorine, nitrogen, and sodium

Show second PowerPoint Presentation

Rules for Lewis Dot Structures Find the total # of VALENCE electrons. - If there is a negative charge, ADD AN ELECTRON - If there is a positive charge, SUBTRACT AN ELECTRON Decide the central atom - The central atom is usually the atom that is LEAST electronegative (except for H) - Occasionally, you will need to choose the unique atom Connect the central atom with the outer atoms - Lines are known as “bonds” - Every bond counts for two electrons Place remaining electrons on peripheral atoms and fill this atom up to 8 valence electrons

EXAMPLES CS2 SCl4

If you need additional help… How to Name Covalent, Molecular Compounds https://www.youtube.com/watch?v=DejkvR4pvRw How to Draw Lewis Dot Structures https://www.youtube.com/watch?v=p7Fsb21B2Xg