Element vs. Compound Table 1. Chemical FormulaElement or Compound? FeElement C Cl 2 Element FeCl 2...
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Transcript of Element vs. Compound Table 1. Chemical FormulaElement or Compound? FeElement C Cl 2 Element FeCl 2...
Element vs. Compound
Table 1.
Chemical Formula Element or Compound?
Fe Element
C Element
Cl2 Element
FeCl2 Compound
CCl4 Compound
1. What does the subscript 2 indicate in Cl2?
• There are 2 Cl atoms.
2. What is implied if there is no subscript?
• There is only 1 atom present.
3. Classify C, Fe, and Cl as metals or nonmetals.
• C• Fe• Cl
nonmetalmetalnonmetal
4. True or False: “The formulas for elements never contain a subscript.”
• False: –Cl2 is an element, but it has a subscript
5. Would you expect the formula S8 to represent a compound or an element?
• Element
6. Why?
• There is only 1 type of atom present.
7. Classify as element or compound.
• Co• CsOH• NaBr• PF5
• CO• H2O• HCl
element compound• CaCl2
• Br2
• SiO2
• P4
• KCl• O2
• Ag
compound elementcompound compoundcompound elementcompound compoundcompound elementcompound element
Honors Chemistry 12/17/13
“It is quality rather than quantity that matters.” – Lucius Annaeus
DO NOW:
1. In your notes: What part of the atom contains almost all of the atom’s mass?
AGENDA:
2. Students will be able to describe the difference between an ionic and covalent compound by reviewing our worksheet.
HOMEWORK:
1. Finish book work from last week for tomorrow.
ANNOUNCEMENT:
1. Science club is meeting today!
In your textbook: read section 7.2 (starts on page 210) and answer the following questions:
On page 232: numbers 60, 62, 63, 64, 66, 67
8. What clues are given in chemical formulas to differentiate between an element and a
compound?
• Multiple capital letters
Notes
• Subscript number = number of each atom present• No subscript = 1 atom present
• Element: made up of only 1 type of atom–may have more than 1 atoms
Notes
• Diatomic Elements–2 atoms present–Only certain elements exist as diatomic
in nature• Uncle HOFBrINCl–H2 O2 F2 Br2 I2 N2 Cl2
Notes
• Compound: made up of more than 1 type of atom–May have metals or nonmetals or both
Ionic or Covalent Bond?
Table 2.
Ionic Compound Covalent Compound
ZnCl2 CCl4
Na2O P2O5
Fe2O3 N2O4
CuI NI3
1. The compound ZnCl2 is considered to be _____ compound.
• Ionic Compound
2. The compound that contains N and O is a ______ compound.
• Covalent Compound3. Does the classification appear to be
based on how many atoms are present?
• No.
4. Write the symbols for each element present in Table 2.
Ionic CovalentZnCl2 CCl4
Na2O P2O5
Fe2O3 N2O4
CuI NI3
Zn
ClNaO
Fe CuI
CPN
• Ionic = metal + nonmetal• Covalent = nonmetal + nonmetal
6. Classify as ionic or covalent.
• NaBr• OF2
• CsF2
• SF6
• NO2
• CrCl3
ioniccovalent
• CoBr2
• BaS• CO2ionic
covalentcovalentionic
ionicioniccovalent
Notes
• Ionic Compound = a compound with a bond between a metal and a nonmetal
• Covalent Molecules = a compound with a bond between 2 or more nonmetals
Octet Rule
• Atoms tend to gain, lose, or share electrons so that they have 8 electrons in their outershell.
1. Potassium has ____ valence electrons.a. To achieve the octet rule, it would
be easier for potassium to ___________ electrons. (gain/lose)
b. This would make potassium a _____________. (cation/anion)
c. This is the symbol for potassium’s ion: _________
1
lose
cation
K1+
2. Magnesium has ____ valence e-s.a. To achieve the octet rule, it would
be easier for magnesium to ___________ electrons. (gain/lose)
b. This would make magnesium a _____________. (cation/anion)
c. This is the symbol for magnesium’s ion: _________
2
lose
cation
Mg2+
3. Boron has ____ valence electrons.a. To achieve the octet rule, it would
be easier for boron to ___________ electrons. (gain/lose)
b. This would make boron a _____________. (cation/anion)
c. This is the symbol for boron’s ion: _________
3
lose
cation
B3+
4. Nitrogen has ____ valence electrons.a. To achieve the octet rule, it would
be easier for nitrogen to ___________ electrons. (gain/lose)
b. This would make nitrogen an _____________. (cation/anion)
c. This is the symbol for nitrogen’s ion: _________
5
gain
anion
N3-
5. Oxygen has ____ valence electrons.a. To achieve the octet rule, it would
be easier for oxygen to ___________ electrons. (gain/lose)
b. This would make oxygen an _____________. (cation/anion)
c. This is the symbol for oxygen’s ion: _________
6
gain
anion
O2-
6. Chlorine has ____ valence electrons.a. To achieve the octet rule, it would
be easier for chlorine to ___________ electrons. (gain/lose)
b. This would make chlorine an _____________. (cation/anion)
c. This is the symbol for chlorine’s ion: _________
7
gain
anion
Cl1-
7. Why are noble gases inert?
• Reactions are movements of electrons.• Noble gases already have 8
valence electrons.• They don’t need to interact
with any other elements.
8. What’s the relationship between the charge of an ion and its location in the
periodic table?
• Elements in the same group tend to have the same charges for their ions.
Where do the electrons go …when an atom loses an
electron?
To another ATOM!
Where does the electron come from….
when an atom gains an electron?
From another ATOM!
Ionic Bonding
• A bond formed between 2 ions by the transfer of electrons
Ionic Bonding
• Usually between a metal and a nonmetal–Metals lose electrons –Nonmetals gain electrons
http://www.youtube.com/watch?v=5IJqPU11ngY
Ionic Bonding
Ionic Bonding
Ionic Bonding
Lewis Dots and Ionic Bonding