Compounds, Chemical Formulas, and
Chemical Equations
Prior Knowledge
Recall our study of elements on the periodic table.
Period Table of the Elements
Link what you know to something new
Let’s Compare Elements and compounds
Elements CompoundsPure PureOne type of atom Two or more atoms
chemically combine together
Can be separated by nuclear reactions
Can be separated by chemical reactions
Examples: gold, silver, aluminum
Examples: water, carbon dioxide, sodium chloride
http://gallery.hd.org/_exhibits/natural-science/_more1998/_more01/water-drops-1-AJHD.jpghttp://www.mortonsalt.com/images/products/IodizedPlain_Salt.jpghttp://www.24hourmuseum.org.uk/content/images/2004_0300.JPG
Salt water, rust
Hydrogen Peroxide Use to cleansea cut or scrapeon your skinH2 O2
http://web1.caryacademy.org/chemistry/rushin/StudentProjects/CompoundWebSites/2000/HydrogenPeroxide/home.htm
Compound Two or more elements combined
chemically.
Sometimes elements or compounds chemically combine. This can be show using chemical formulas and chemical equations.
Examples of Chemical Formulas and Equations
CO2 + H2O = (H2CO3)
Carbon dioxide + water = carbonic acid (soda fizz)
Ag + S = Ag2S
Silver + sulfur = sulfur sulfide (tarnish)
When you take the cap off a bottle of soda, bubbles rise to the top of the bottle as carbonic acid breaks down into carbon dioxide and water.
Tarnished Silver
Chemical formula Scientific short way of describing the
chemical content of a substance. Number and letters stand for how many and what kinds of atoms are in one molecule of the chemical. For example: In CO2, the C stands for carbon and the O stands for Oxygen. There are two atoms of oxygen and one atom of hydrogen.
Chemical Equation Is a statement that uses chemical formulas
to express the identities and quantities of the substances involved in a chemical or physical change
Engage Balloon gas
Explore
Sweet Models Lab
Explain Review vocabulary Provide examples of compounds, chemical
formulas and chemical equations Relevance
Elaborate
So Happy Together!
Evaluate1. In a molecule of fruit sugar, C6H12O6, how
many carbon atom are there? Hydrogen? Oxygen?
2. Which formulas represent compounds? Elements? (NaCl, Ag, Co, CO, SO2, AgBr)
3. Nitrogen in the air is two nitrogen atoms attached together, N2. Is this nitrogen a compound
or element? How do you know?
4. How many molecules of copper are produced from two molecules of Cu2O?
5. What happens to atoms in a chemical reaction?
6. What physical properties can change in a chemical reaction?
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