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Do Now:. Define the following words in your notebook: Element Compound Ion Polyatomic ion. Element. A substance that cannot be changed into simpler substances under normal laboratory conditions. Compound.
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Do Now: • Define the following words in your notebook: • Element • Compound • Ion • Polyatomic ion
Element • A substance that cannot be changed into simpler substances under normal laboratory conditions
Compound • a substance that can be separated into simpler substances (elements or other compounds) only by chemical reactions (made of 2 or more elements)
Ion • An atom or group of atoms that has a positive or negative charge • Cations ions with a POSITIVE CHARGE (because they lost electrons) • Anions ions with a NEGATIVE CHARGE (because they gained electrons)
Polyatomic Ion • A covalently bounded group of atoms that behave as one whole unit and carry one single charge.
Metals VS Nonmetals Notes about Charge:
Ionic Compounds • A compound composed of positive and negative ions • How to recognize an ionic compound … • Cation and anion • Metal and nonmetal • + and -
Rules for Writing Formulas - Ionic Compounds • Write the symbol for cation first with charge • Write the symbol for anion with charge • Criss Cross charges • Reduce (if necessary) * Never leave + or – in a formula * Never use 1’s in a formula
Writing Ionic Formulas-Examples: Steps: • Write cation first with charge • Write anion with charge • Cris Cross charges • Reduce (if necessary) *Never leave + or – in a formula * Never use 1’s • Bromine and Calcium 2. Magnesium and Sulfur
TRY “Writing Ionic Formulas” #1-5 Potassium and Oxygen Lithium and Sulfur Aluminum and oxygen Magnesium and nitrogen Strontium and sulfur Potassium and phosphorous
Transition Metals • Metals that have multiple charges • Charges are represented by roman numerals (in names only) • Roman numerals are NOT used in formulas EXCEPTIONS: (These only have one specific charge) • Silver Ag1+ • Zinc Zn2+ • Cadmium Cd2+ MEMORIZE THESE! Sn, Sb, Tl, Pb and Bi are also considered transition metals.
Writing Ionic Formulas(with transition metals)-Examples: Steps: • Write cation first with charge • Write anion with charge • Cris Cross charges • Reduce (if necessary) * Never leave + or – in a formula * Never use 1’s • Iron (II) and oxygen 2. Copper (I) and iodine
TRY “Transition Metals and Non Metals” #1-3 Iron (III) and oxygen Lead (IV) and nitrogen Zinc and bromine Nickel (I) and iodine
Writing Ionic Formulas(with polyatomics)-Examples: Steps: • Write cation first with charge • Write anion with charge • Cris Cross charges • Reduce (if necessary) * Never leave + or – in a formula * Never use 1’s * Use ( ) when more than one p.i. • Magnesium nitrate 2. Sodium hydroxide 3. Lead (IV) sulfate