Transcript WHO AM I? - De Anza College

Alex, Jerry, Tin
Chemistry Group
1.
2.
How many kinds of and numbers
of does one compound have?
How many charge does one
atom has?
Octet Rule
atoms tend to combine in such
a way that they each have
eight electrons in their valence
shells, giving them the
same electronic
configuration as a noble gas
Periodic Table
Sodium Chloride?
1. What are the atoms symbol?
Sodium?
Na.
Chlorine?
Cl.
Periodic Table
2. Determine the number of
valence electrons.
Na?
1
Cl?
7
Periodic Table
3. Apply octet rule.
Want to make 8 electrons
4. Determine the charge
Na has 1 valence electron, it is more
stable to lose 1 electron.
Na+
Cl has 7 valence electrons and
easier to gain 1 electron.
ClPeriodic Table
+
Na
Cl
Happily Married
Aluminum Oxide
1. What are the atoms symbol?
Aluminum?
Al.
Oxygen?
Cl.
Periodic Table
2. Determine the number of
valence electrons.
Al?
3
O?
6
Periodic Table
3. Apply octet rule.
Want to make 8 electrons
4. Determine the charge
Al has 3 valence electrons, it is
more stable to lose 3 electrons
than gain 5 electrons.
Al3+
Periodic Table
O has 6 valence electrons and
easier to gain 2 electron.
O2-
Periodic Table
Since O can gain only 2 electrons from Al, as a
result, Al can still give up one more electron.
There are second O to grab lost electron from Al.
But now the second O only has 7 electrons and
wants one more.
It steals one more electrons from another Al.
Now the second Al want to lose 2 more electrons
which will be grabbed by the third O.
3+
2Al2 O3
happily Married again