CompoundsCompounds
CompoundCompound: :
a substance made up of a substance made up of atoms of different elements atoms of different elements joined together (involves a joined together (involves a chemical change) chemical change)
ExampleExample: :
*There is no atom of water.*There is no atom of water.
*Two atoms of hydrogen join with one *Two atoms of hydrogen join with one atom of oxygen. (chemical bond)atom of oxygen. (chemical bond)
*The smallest unit of water is called a *The smallest unit of water is called a molecule.molecule.
Chemical FormulaChemical Formula: :
the arrangement of the arrangement of symbols and numbers symbols and numbers that describe a compound that describe a compound
ExamplExample: e:
HH22O O
H = Hydrogen H = Hydrogen
How many atoms of How many atoms of hydrogen? hydrogen?
2 atoms of hydrogen2 atoms of hydrogen
O = OxygenO = Oxygen
• If there is no number behind the If there is no number behind the element symbol, there is just one element symbol, there is just one atom of that element.atom of that element.
• Therefore, there is only 1 atom of Therefore, there is only 1 atom of oxygen in Hoxygen in H220.0.
NaClNaCl
How many elements? How many elements? 2 2
Name of elements Name of elements Sodium, chlorine Sodium, chlorine
Atoms of each element Atoms of each element Na = 1 Na = 1
Cl = 1 Cl = 1
Total # of atoms Total # of atoms 2 2
Name of compound Name of compound Table Salt Table Salt
Your TurnYour Turn
Other Chemical FormulasOther Chemical Formulas
one atom of nitrogen one atom of nitrogen
two atoms of oxygen two atoms of oxygen
NONO22
nitrogen dioxidenitrogen dioxide
aluminum oxide aluminum oxide
two atoms of aluminumtwo atoms of aluminum
three atoms of oxygenthree atoms of oxygen
AlAl22OO3 3
acetyleneacetylene
two atoms of carbontwo atoms of carbon
two atoms of hydrogentwo atoms of hydrogen
CC22HH22
sodium carbonatesodium carbonate
two atoms of sodiumtwo atoms of sodium
one atom of carbonone atom of carbon
three atoms of oxygenthree atoms of oxygen
NaNa22COCO33
glucoseglucose
six atoms of carbonsix atoms of carbon
twelve atoms of hydrogentwelve atoms of hydrogen
six atoms of oxygensix atoms of oxygen
CC66HH1212OO66
ammoniaammonia
one atom of nitrogenone atom of nitrogen
three atoms of hydrogenthree atoms of hydrogen
NHNH33
benzenebenzene
six atoms of carbonsix atoms of carbon
six atoms of hydrogensix atoms of hydrogen
CC66HH66
Recipes for Compound Molecules Recipes for Compound Molecules
Write the following as a formula: Write the following as a formula:
# 1. hydrogen peroxide# 1. hydrogen peroxide
two atoms of hydrogen, two atoms of two atoms of hydrogen, two atoms of oxygenoxygen
HH22OO22
Here are some formulas. Here are some formulas. You write out the recipe.You write out the recipe.
# 1. aluminum phosphate # 1. aluminum phosphate
AlPOAlPO44
one atom of aluminumone atom of aluminum
one atom of phosphorusone atom of phosphorus
four atoms of oxygenfour atoms of oxygen
Do you know how to read Do you know how to read formulas? Read through the formulas? Read through the following formulas for molecules following formulas for molecules of different compounds. Then of different compounds. Then tell how many different elements tell how many different elements and atoms are in each molecule.and atoms are in each molecule.
# 4. Fe# 4. Fe22OO33
# of elements# of elements 22
# of atoms# of atoms 55
common namecommon name rustrust
Click for Video Clip on Compounds
Top Related