Today’s Agenda Bill Nye Chemical Reactions Video (DyKnow questions) Chemical Reactions Tab Chemical Reactions Notebook/Vocabulary

Answer the questions as you watch the video:

Chemical Reaction Notes

Chemical Formula An expression that shows the number and type of atoms joined in a compound (molecule). How many atoms of sulfur (S)? How many atoms of Oxygen (O)? SO2

SO2 subscript Subscript A number written slightly below and to the right of a chemical symbol that shows how many atoms of an element are in a compound (molecule). subscript SO2

Coefficient 4SO2 The number before a chemical formula that indicates how many sets of the compounds (molecules) are involved in a reaction. So, its basically telling you there are four SETS of SO2. How many atoms of Sulfur (S)?_____ How many atoms of Oxygen (O )?_____

Submit when you’re done. Part A: Identify the following parts of each chemical formula by circling the subscripts and drawing a square around the coefficients. Part B: List the symbols for the atoms in each formula and give the number of each. Carbon- ______ Hydrogen- _____ Magnesium- ______ Oxygen- _____ Phosphorous- ______ Oxygen- _____ Aluminum- ______ Oxygen- _____ Hydrogen- ______ Nitrogen-______ Hydrogen- _____ Hydrogen- ______ Oxygen- _____

Chemical reaction The process by which chemical changes occur. There are five signs of a chemical reaction: 1) color change 2) temperature change 3) bubble formed 4) precipitate forms 5) irreversible change occurs In a chemical reaction, atoms are rearranged, and chemical bonds are broken and formed.

BaCl2 + H2SO4 → BaSO4 + 2 HCl Chemical equation reactants → products a way of writing out the reactants and products in a chemical reaction. reactants → products Reactant Products BaCl2 + H2SO4 → BaSO4 + 2 HCl A substance that is present at the beginning of a chemical reaction and is changed to a new substance A substance formed by a chemical reaction. A product is made by the rearrangement of atoms and bonds in reactants.

Submit when you are done. Highlight the reactants in lime. Highlight the products in aqua.

2 Mg + O2 → 2 MgO + energy(heat) Exothermic reaction a type of reaction that releases energy. 2 Mg + O2 → 2 MgO + energy(heat) energy/heat on the right side of the arrow meaning its getting hotter or colder.

2 Mg + O2 + energy(heat) → 2 MgO Endothermic reaction a type of reaction that absorbs energy. 2 Mg + O2 + energy(heat) → 2 MgO energy/heat on the left side of the arrow meaning it needs energy to start the chemical reaction

Reaction Rate how fast or slow a reaction takes place; how fast reactants change to products. Five factors effect the rate of a reaction: Concentration(amount) Surface area Catalyst Inhibitor Temperature

Activation Energy the energy needed to start a chemical reaction

Five factors effect the rate of a reaction: Concentration(amount) of reactants- the more you have the slower the reaction rate. Surface area of reactants- The smaller the space the reaction occurs in the faster the reaction rate Catalyst- a chemical that is used to lower the activation energy, the energy needed to start a chemical reaction, and make the reaction occur faster Inhibitor- a chemical that is used to increase the activation energy and make the reaction occur slower Temperature- the higher the temperature the faster the reaction occurs.

Vocabulary Chemical formula Subscript Coefficient Chemical reaction Chemical equation Reactant Product Exothermic Reaction Endothermic Reaction Reaction Rate Activation Energy Catalyst Inhibitor