Activator Complete the activator on today’s classwork sheet

Chemical reactions September 27, 2017

Objective SWBAT: identify the rearrangement of atoms in chemical reactions.

Connection Yesterday we started talking about chemical reactions and how the law of conservation of mass applies to reactions. Today we are going to continue to see that this is true by practicing counting atoms for both reactants and products in chemical equations.

Chemical Reactions Chemical reactions happen when two or more substances (reactants) interact and form a new substance (product). The new substances, can be completely different than the original substances, and have different properties.

Chemical Reactions Chemical reactions can be represented by chemical equations. Chemical equations have three parts: Reactants (on the left) Products (on the right) Yield symbol (in the middle, like an equal sign)

Chemical Reactions Remember the Law of Conservation of Mass! The number of atoms on the reactant side has to be equal to the number of atoms on the product side!

Chemical Equation example Photosynthesis 6CO2  + 6H2O + Sunlight  C6H12O6  + 6O2 Carbon Dioxide + Water + Sunlight  Sugar + Oxygen How many atoms are there on each side of the yield sign?

Chemical Equation example Cellular Respiration C6H12O6 + 6 O2  6 CO2 + 6 H2O Sugar + Oxygen  Carbon Dioxide + Water How many atoms are there on each side of the yield sign?

Independent work Complete the practice problems for counting atoms. Make sure that all of the chemical reactions shown are supporting the law of conservation of matter.

Exit TIcket How are chemical equations in science class similar to equations in math class? Homework is to study for a quiz on Friday!