Naming Chemical Compounds and Writing Chemical Formulas

w/e 1/30Warm-ups112 1/26 – 1/29Fat Man Little Boy – Questions and Notes113 1/30Writing Formulas and Naming Compounds Notes 114 1/30Compounds Quiz115

Ionic vs. Covalent Compounds REVIEW  Ionic Compounds – contain a metal and a non- metal (example: sodium chloride (salt) – sodium is a metal /chlorine is a nonmetal)  Covalent – contains only nonmetals (example: hydrogen peroxide – hydrogen is a nonmetal / oxygen is a nonmetal)

More REVIEW  Electrons in the same group have similar chemical properties because they have the same number of electrons in their valence shell  Chemical bonds form between 2 atoms when electrons in the outer shell of each atom form a stable arrangement together  Any atom or group of atoms that carry an electric charge is called an ion

CATIONS – Positively Charged  When a neutral atoms gives up an electron, the positively charged ion is called a CATION  All alkali metals (Group 1) form cations very easily  They require little energy to remove that valence electron

ANIONS – Negatively Charged  Non-metals gain electrons to obtain a noble gas arrangement – ANIONS  Halogens (group 17) must gain an electron to do so  Halogens gain an electron easily and release a great deal of energy – therefore, they too are very reactive  Chemical reactivity decreases as you move down the group

 Substances that are composed of anions and cations are called IONIC COMPOUNDS  Ionic Bond – the attraction between oppositely charged ions Ionic Bond  Bond between a metal and a non-metal  Covalent Bond – atoms that share a pair of electrons Covalent Bond  Bond between 2 or more non-metals

Ionic Compound Names EXAMPLE : Al 2 O 3 1. The subscript for this compound indicates that there are two atoms of aluminum and three atoms of oxygen. These numbers do NOT affect the name. 2. The first part of the name would be aluminum (the metal). 3. The second part of the name, we drop the ending on oxygen (non-metal) and add – ide, thus it becomes oxide Ionic Compound Name – aluminum oxide

Ionic Compound Names  The first part of the name is the name of the metal element.  The second part of the name is the name of the nonmetal element with the ending changed to the suffix – ide

Ionic Compound Naming - Practice  NaCl  KF  MgF 2  CsCl  BaCl 2  NaI  Mg 3 N

Ionic Compound Naming - Practice Sodium Chloride Potassium Fluoride Magnesium Fluoride Cesium Chloride Barium Chloride Sodium Iodide Magnesium Nitride NaCl KF MgF 2 CsCl BaCl 2 NaI Mg 3 N

Sodium chloride MetalNon-metal NaCl -I-Identify the chemicals as either a metal, transitional metal or non-metal -W-Write out the chemical symbols of each CROSS-OVER RULE

sodium chloride metalnon-metal NaCl NaCl Identify the metal and non-metal i.) Write the symbols ii.) Write the charges iii.) Cross-over the charges from top to bottom iv.) Remove the charge v.) Simplify the numbers and remove the 1’s

NaCl *REMEMBER, that metals lose electrons and non- metals gain electrons +1 Opposites Attract

Calcium oxide metalnon-metal CaO CaO Identify the metal and non-metal i.) Write the symbols ii.) Write the charges iii.) Cross-over the charges from top to bottom iv.) Remove the charge v.) Simplify the numbers and remove the 1’s

CaO *REMEMBER, that metals lose electrons and non- metals gain electrons Opposites Attract

magnesium chloride metalnon-metal MgCl MgCl 2 Identify the metal and non-metal i.) Write the symbols ii.) Write the charges iii.) Cross-over the charges from top to bottom iv.) Remove the charge v.) Simplify the numbers and remove the 1’s

Mg Cl Cl +2 MgCl 2

calcium phosphide metalnon-metal CaP Ca 3 P 2 Identify the metal and non-metal i.) Write the symbols ii.) Write the charges iii.) Cross-over the charges from top to bottom iv.) Remove the charge v.) Simplify the numbers and remove the 1’s

PRACTICE QUESTIONS Beryllium fluorideBarium bromide Sodium nitrideGallium sulfide Calcium sulfideZinc bromide Aluminum chlorideCesium phosphide Lithium phosphideGermanium oxide BeF 2 Na 3 N CaS AlCl 3 Li 3 P BaBr 2 Ga 2 S 3 ZnBr 2 Cs 3 P GeO 2

More Rules for Ionic Compounds  If the compound has more than 2 elements (polyatomic), the second name is one of the following: Oxidation # NO 2 nitrite1- NO 3 nitrate1- OH hydroxide1- PO 4 phosphate3- CO 3 carbonate2- SO 4 sulfate2-

Practice!!  Sodium Nitrate  Sodium Hydroxide  Sodium Phosphate  Calcium Carbonate

Naming Compounds that use a COVALENT BOND to join two atoms together (nonmetal and nonmetal)  BINARY Molecular Formulas – Binary molecules will only have TWO elements in their formula.  The names of the compounds will include a prefix to indicate the number of atoms of each element.

CORRECTION ABOVE! – The number one is MONO! Have you seen any of these prefixes before? The prefixes are very similar to the prefixes of geometric shapes. You know what a triangle is. Right? Well the prefix tri- means three. So when you have three chlorine (Cl) atoms, you would name it trichloride.

 Just like when you are naming an ionic compound the second elements name is changed to end in -ide.  EXCEPTION - An exception to using prefixes is when the first element has only one atom. The prefix (mono) is not used in this instance.  Example: CO 2 - Carbon Dioxide

Naming Practice – Binary Covalent Compounds Naming Practice  CCl 4  S 4 N 2  CO  CO 3  OF 2

Naming Practice – Binary Covalent Compounds  CCl 4  S 4 N 2  CO  CO 3  OF 2 Carbon tetrachloride Tetrasulfur dinitride Carbon monoxide Carbon trioxide Oxygen difluoride