Presentation on theme: "Symbols X A Z Na 23 11. Chemical Bonds n The forces that hold atoms together. n Covalent bonding - sharing electrons. n Makes molecules. n Chemical formula-"— Presentation transcript:
Chemical Bonds n The forces that hold atoms together. n Covalent bonding - sharing electrons. n Makes molecules. n Chemical formula- the number and type of atoms in a molecule. n C 2 H 6 - 2 carbon atoms, 6 hydrogen atoms, n Structural formula shows the connections, but not necessarily the shape.
H H HH H HCC n There are also other model that attempt to show three dimensional shape. n Ball and stick.
Ions n Atoms or groups of atoms with a charge. n Cations- positive ions - get by losing electrons(s). n Anions- negative ions - get by gaining electron(s). n Ionic bonding- held together by the opposite charges. n Ionic solids are called salts.
Polyatomic Ions n Groups of atoms that have a charge. n Yes, you have to memorize them. n List on page 221
Writing Formulas n Two sets of rules, ionic and covalent n To decide which to use, decide what the first word is. n If is a metal or polyatomic use ionic. n If it is a non-metal use covalent.
Ionic Formulas n Charges must add up to zero. n Get charges from table, name of metal ion, or memorized from the list. n Use parenthesis to indicate multiple polyatomics.
Ionic Formulas n Sodium nitride n sodium- Na is always +1 n nitride - ide tells you it comes from the table n nitride is N -3
Ionic Formulas n Sodium nitride n sodium- Na is always +1 n Nitride - ide tells you it comes from the table n nitride is N -3 n Doesn’t add up to zero. Na +1 N -3
Ionic Formulas n Sodium nitride n sodium- Na is always +1 n nitride - ide tells you it comes from the table n nitride is N -3 n Doesn’t add up to zero n Need 3 Na Na +1 N -3 Na 3 N
Ionic Compounds n Sodium sulfite n calcium iodide n Lead (II) oxide n Lead (IV) oxide n Mercury (I) sulfide n Barium chromate n Aluminum hydrogen sulfate n Cerium (IV) nitrite
Naming compounds n Two types n Ionic - metal and non metal or polyatomics. n Covalent- we will just learn the rules for 2 non-metals.
Naming Ionic compounds n If the cation is monoatomic- Name the metal (cation) just write the name. n If the cation is polyatomic- name it. n If the anion is monoatomic- name it but change the ending to –ide. n If the anion is poly atomic- just name it n Practice.
Ionic Compounds n Have to know what ions they form off table, polyatomic, or figure it out n CaS nK2SnK2SnK2SnK2S n AlPO 4 n K 2 SO 4 n FeS n CoI 3
Ionic Compounds n Fe(C 2 O 4 ) n MgO n MnO n KMnO 4 n NH 4 NO 3 n Hg 2 Cl 2 n Cr 2 O 3
Ionic Compounds n KClO 4 n NaClO 3 n YBrO 2 n Cr(ClO) 6
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