Download - Class Notes: Elements and
Elements and Compounds Notes 2016.notebook January 15, 2019
Class Notes: Elements
and Compounds
They are both "Pure Substances"
Periodic table asap 2 min.https://www.youtube.com/watch?v=VgVQKCcfwnU&t=2s
WHAT IS A
"PURE SUBSTANCE?"
Elements and Compounds Notes 2016.notebook January 15, 2019
Pure substance: When all the particles in a substance are alike
What are four examples?
What is the simplest pure substance?
If you melt IRON, does it become a simpler substance?
WHY NOT???
Atom: Smallest part of an element that has the properties of that element.
Chemical symbol: Shorthand way to write the elements: Carbon ____ Hydrogen ____ Calcium ___ Gold ____
Atom: Smallest part of an element that has the properties of that element.
Chemical symbol: Shorthand way to write the elements: Carbon ____ Hydrogen ____ Calcium ___ Gold ____
Elements and Compounds Notes 2016.notebook January 15, 2019
Compound: Two or more elements chemicallycombined
Carbon + Oxygen = Carbon Dioxide= CO2
Hydrogen + Oxygen = Water= H2 O
Sodium + Chlorine = Sodium Chloride= NaCl
Elements Compound
Na Cl
Properties of the elements are very different than properties of the compound itself.
Highly reactive! Poisonous! We put on food!
https://www.youtube.com/watch?v=ODf_sPexS2Q
Elements and Compounds Notes 2016.notebook January 15, 2019
Compounds: Pure substances made of more than one elementWater = Carbon dioxide =
Molecules: Pure substances: 2 or more atoms chemically bonded together.
2 atoms of oxygen = O2
2 atoms of chlorine = Cl2Molecule but not compound!! (same element)
2 atoms hydrogen + one of oxygen = H2 OMolecule and compound!!
Chemical Formula: Combinations of chemical symbols to represent chemical substances. Ammonia = NH
Rubbing Alcohol = C H OH
Coefficient: Large number in front that tells you how many of that formula
3 7
3
2H2O
Ammonia Elements:
Alcohol Elements:
Elements and Compounds Notes 2016.notebook January 15, 2019
Where is Subscript placed: to right of element symbol
What does Subscript tell you? The number of atoms of element in the compound
When there's only One atom, the subscript 1 is ______ written.
Coefficient: Large number in front that tells you how many of that formula
Subscript
2H2O
Elements and Compounds Notes 2016.notebook January 15, 2019
Chemical Formula for Carbon Dioxide
How many atoms of carbon? _____ oxygen? ____
If chemical symbols are like letter, and chemical formulas
are like words, chemical equations are like SENTENCES!
Elements and Compounds Notes 2016.notebook January 15, 2019
Chemical Equation: Shorthand method to describe chemical reactions using chemical formulas and other symbols
C + O2 CO2
Chemical Equation for Carbon Dioxide
Elements and Compounds Notes 2016.notebook January 15, 2019
The Law of Conservation of Mass:The mass of all substances BEFORE a chemical reaction is the SAME as AFTER the chemical reaction!
(Count the atoms!)
Elements and Compounds Notes 2016.notebook January 15, 2019
Does this reaction show Law of Conservation of Mass?
Learn to Count Atoms!
Elements and Compounds Notes 2016.notebook January 15, 2019
LET'S PRACTICE COUNTING!
2.
3.
4.
5.
CarbonOxygen
Elements and Compounds Notes 2016.notebook January 15, 2019