Transcript CHEMISTRY

CHEMISTRY
The good news and
the bad news
It’s all
about
building
blocks
Hydrogen
Carbon-6
Compounds are two
or more elements
that share electrons
or have taken or
given electrons away.
Hydrogen
Hydrogen
Hydrogen
Atoms combine to form
compounds in simple ratios, such
as 1:1, 1:2, 2:2, 1:3, and so forth.
Chemical Equations are simple.
2H2 + O2  2H2O
O
H
O
Ba
O
H
Ca
O S
O
O
Ba(OH)2(aq) + CaSO4(aq)  BaSO4(s) + Ca(OH)2(aq)
Good news: Your car rolled off the pier but didn’t fall into the water.
Bad news: The damage to the yacht is more than the value of the car.
Imagine counting grains of sand.
Not easy but not impossible.
Now imagine trying to count
grains of sand that are 2,000
miles away. Quite impossible
even with the world’s best
telescope.
Well this is the challenge in
counting atoms. Counting atoms
from 1 foot away is the same as
counting grains of sand 2,000
miles away.
Chemical Equations are simple.
2H2 + O2  2H2O
Chemical equations are quite easy. Here we count out 4
hydrogens and 2 oxygen atoms and we can make two
water molecules. But how many hydrogens and oxygens
would we count out to make enough water to fill a one liter
bottle of water?
Imagine the number of grains of
sand in a handful of sand:
thousands or maybe a million?
It would be difficult to count that
many. Now imagine the number
of grains of sand that would be
present if we covered all of the
Earth (land and sea) 10 miles
deep of sand. That number of
grains of sands is the same
number of water molecules
needed to fill a 1 liter bottle.
The numbers
under the element
names are the
relative weights.
However, if you
consider one
mole of the
element (6 x 1023
atoms) then these
numbers are read
as grams.
Bridge between
mass and number