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?