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Compounds. Types, Naming & Explaining. I can explain the properties of ionic & molecular compounds. Learning Goals. Background Information do not copy down the following slides. Types of compounds.
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Compounds Types, Naming & Explaining
I can explain the properties of ionic & molecular compounds. Learning Goals
Types of compounds • The millions of types of compounds that have been discovered and described can be categorized as one of two types: • Ionic • Molecular
Ionic Compounds • Composed of at least one metal and one nonmetal. • Most share the following properties: • High melting points • Form crystals, very regular arrangements of particles • Dissolve in water to form solutions that conduct electricity • Solids at room temperature • Example: NaCl (salt)
How do Ionic Compounds form? • The transfer of electrons from the metal to the nonmetal. • Causes metal to form positive ion and nonmetal to form negative ion. • Opposites attract and they arrange themselves in an alternating pattern called a crystal arrangement.
Molecular compounds • When two or more non-metals combine together. • Atoms SHARE electrons to obtain stability. • Example: Sugar (C12H22O11) • Share the following properties: • Can be solids, liquids or gases • Usually good insulators but poor conductors • Have relatively low boiling points
Step #3 Naming Step #1 Step #4 Naming Step #1 Step #2 Yes Step #1 No Step #3 Naming Step #1 Step #4 Naming Step #2 Step #2 Step #5 Naming Step #3
QUESTION Is the first element a metal?
It’s an ionic compound • It’s made up of a metal and a non-metal. • Example: CaCl2 Name: __________ _________
Naming Step #1 • Write down the name of the element that is the METAL (the first element in the formula) • Example: CaCl2 Name: Calcium _________
Naming step #2 • Name the non-metal element second. The ending of its name changes to “ide” • Example: CaCl2 Name: Calcium Chloride
It’s an Molecular compound • It’s made up of two non-metals • Example: N2O5 Name: __ ________ __ _______
Naming Step #1 • Write down the name of the first element. • Example: N2O5 Name: __nitrogen __ _______
Naming step #2 • Name the second element. The ending of its name changes to “ide” • Example: N2O5 Name: __nitrogen __oxide
Naming step #3 • Add prefixes indicating the number of atoms of each element. • Example: N2O5 Name: dinitrogenpentaoxide Prefixes You Need to Know: Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5 Hexa = 6 Hepta = 7 Octa = 8
Ionic Compound Step #1 Ionic Compound Step #2a Ionic Compound Step #3a Ionic Compound Yes Ionic Compound Step #2b Ionic Compound Step #3b The Question No Molecular Compound Step #2 Molecular Compound Molecular Compound Step #1
QUESTION Is the first element a metal?
Ionic Compounds Step #1 • Identify the ions and their charges. • Example: aluminum oxide 3+ 2- • Rough work: Al O
Ionic Compounds Step #2a O2- Al3+ Al3+ O2- O2- O2- O2- Al3+ Al3+ Al3+ O2- O2- O2- Al3+ 3 atoms Total = 2 atoms Picture the charges sitting on a teeter-totter. How many of each atom would you need to balance out each side? Example: aluminum oxide 3+ 2- Rough work: Al O
Ionic Compounds #3a Al3+ O2- O2- O2- Al3+ 3 atoms Total = 2 atoms Write the final of ratio of atoms in the element. Example: aluminum oxide Answer: Al2O3
Molecular compound Chemical formulas: Part #1 • Write the symbols for each of the elements in the compound. • Example: nitrogen trifluoride Formula: N F
Molecular compound Chemical formulas: Part #2 Prefixes You Need to Know: Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5 Hexa = 6 Hepta = 7 Octa = 8 • Write the subscript to indicate the number of atoms based on the prefix. Do not write the number 1. • Example: nitrogen trifluoride Formula: N F3