Do Now: Explain this joke.
The last 2 weeks we have… investigated how evidence of chemical reactions indicates that new substances with different properties are formed.
Evidence of a chemical reaction: (chemical change) • Production of a gas (bubbling, fizzing or foaming) • A change in temperature or light (an energy change) • Appearance of a precipitate (solid material) • A change in color
Let’s make some visual models with SKITTLES You will be able to… 8.5(D) recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts; 8.5(F) recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass. • Key • Red-Chlorine • Orange-Sodium • Yellow-Oxygen • Green-Hydrogen • Purple- Carbon
Review: How to make a molecule… Formula Visual model H2O Subscript No Subscript, There is only 1 atom of oxygen in the molecule
Review: How to make a molecule… Formula Visual model H2O No Subscript, There is only 1 atom of oxygen in the molecule Subscript H2O2
Review: How to make a molecule… Formula Visual model 6 H2O Coefficient- How many molecules you have.
H2O 1 molecule of H2O
3 H2O 3 molecules of H2O
Let’s now model another chemical equation with our SKITTLES… 1 atom carbon reacts with 1 molecule of oxygen 1 molecule of CO2 1 carbon 2 oxygen 1 carbon 2 oxygen
Is it a balanced equation? How do we know? 1 molecule CO2 1 atom carbon + 1 molecule oxygen 1 carbon 2 oxygen 1 carbon 2 oxygen
Law of Conservation of Mass Matter is not created or destroyed, it just changes forms. In a chemical reaction…
More practice… 2 atoms carbon react with 2 molecule oxygen 3 molecules CO2 2 carbons 4 oxygen 3 carbons 6 oxygens Is it balanced?
The model above is best represented by: • H2O • 2OH • HOOH • H2O2
The above model shows: • 10 atoms • 2 molecules • 2CH3Cl • All of the above
6CO2+ 6H20+ Sun’s light C6H12O6+6O2 The above reaction… • is photosynthesis • Is respiration • Transforms radiant energy into chemical energy • Both a and c.
Organic Molecules all contain… • Sulfur • Carbon • Oxygen • nitrogen
All of the following are organic molecules except… • C6H12O6 • CH4 • C6H6O • H20