Naming Chemical Compounds and Writing Chemical Formulas we

Naming Chemical Compounds and Writing Chemical Formulas

w/e 1/30 Warm-ups 112 1/26 – 1/29 Fat Man Little Boy – Questions and Notes 113 1/30 Writing Formulas and Naming Compounds Notes 114 1/30 Compounds Quiz 115

Ionic vs. Covalent Compounds REVIEW Ionic Compounds – contain a metal and a nonmetal (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 Bond between a metal and a non-metal Covalent Bond – atoms that share Bond between 2 or more non-metals a pair of electrons

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 Na. Cl KF Mg. F 2 Cs. Cl Ba. Cl 2 Na. I Mg 3 N

Ionic Compound Naming Practice Na. Cl KF Mg. F 2 Cs. Cl Ba. Cl 2 Na. I Mg 3 N Sodium Chloride Potassium Fluoride Magnesium Fluoride Cesium Chloride Barium Chloride Sodium Iodide Magnesium Nitride

CROSS-OVER RULE Sodium chloride Metal Non-metal Na - Cl Identify the chemicals as either a metal, transitional metal or non-metal Write out the chemical symbols of each

metal non-metal sodium chloride Na +1 -1 Na. Cl Cl -1 +1 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

Opposites Attract +1 Na Cl -1 *REMEMBER, that metals lose electrons and nonmetals gain electrons

metal non-metal Calcium oxide Ca +2 -2 Ca. O O -2 +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

Opposites Attract Ca +2 O -2 *REMEMBER, that metals lose electrons and nonmetals gain electrons

metal non-metal magnesium chloride Mg +2 -1 Mg. Cl 2 Cl -1 +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

-1 Cl Mg +2 Mg. Cl 2 Cl -1

metal non-metal calcium phosphide Ca +2 -3 Ca 3 P 2 P -3 +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 fluoride Sodium nitride Calcium sulfide Aluminum chloride Lithium phosphide Be. F 2 Na 3 N Ca. S Al. Cl 3 Li 3 P Barium bromide Gallium sulfide Zinc bromide Cesium phosphide Germanium oxide Ba. Br 2 Ga 2 S 3 Zn. Br 2 Cs 3 P Ge. O 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 NO 3 OH PO 4 CO 3 SO 4 nitrite nitrate hydroxide phosphate carbonate sulfate 111322 -

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 3 OF 2

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