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

2. Answer the questions as you watch the video:

3. Chemical Reaction Notes

4. 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

5. 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

6. 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 )?_____

7. 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- _____

8. 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.

9. 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 → BaSO 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.

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

11. 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.

12. 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

13. 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

14. Activation Energy
the energy needed to start a chemical reaction

15. 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.

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