Chemical Formulas and Equations

1. Chemical Formulas and Equations

2. Chemical Symbol (of elements) • Shows which atoms are present in the element • First letter is always capitalized • Can be 1, 2, or 3 letters Ex: Na (sodium) Ex: C (carbon)

3. Element/Compound Flipbook • In your flipbook, write the names of the following elements. Use the periodic table. • Write if the element is a metal or a nonmetal • Determine the group and period of the element • N 4. H • O 5. Na • C 6. Cl

4. Common Compounds • CO2 Name - __________________ Elements Present - ________________ • NaCl Name - _____________ Elements Present - ____________________________

5. Common Compounds • H2O Name – _________________ Elements present- ______________ • C6H12O6 Name - ________________ Elements Present - _____________

6. Chemical Formulas • Used to show which elements are in a compound • Used to show how many atoms of each elements are in a compound • A capital letter is used to show different elements

7. Subscripts • Small number that follows the letter • Tells you how many atoms of each element are there • If no subscript is there, assume there is 1 atom • Example: • H2O ( H= 2, O = 1) Subscript

8. Now it’s your turn • How many atoms are in the following compounds? • NaCl Na= Cl= • H2O2 H= O= • CO2 C= O= • CH4 C = H=

9. Coefficients • Big number in front of the compound • Tells you how many compounds are present • If no coefficient is there, assume 1 compound • Example: • 2 H2O ( There are two water compounds) Subscript Coefficient

10. How do coefficients and subscripts work together • Multiply the coefficient and each subscript to determine how many atoms of each element are there • Example: • 2 H2O (H= 2 x2 =4 atoms, O=2x1 = 2 atoms) Write a 1 behind oxygen since no subscript is present

11. Now its your turn • Show how many atoms are present by multiplying the coefficient by the subscript. • 2NaCl Na= Cl= • 3H2O2 H= O= • CO2 C= O= • 4CH4 C = H=

12. License Plate Activity • Create a license plate message using the chemical symbols found on the periodic table. • Plate must include at least 3 different elements and either a subscript or coefficient. • On the bottom of the paper include the element names found in the message.

13. Chemical Equation • Used to show a chemical change using symbols instead of words • Example: • Carbon dioxide added to water makes sugar and oxygen gas • CO2 + H2O  C6H12O6 + O2

14. Reactants • The “ingredients” of a chemical reaction • The substances that are mixed together at the beginning of a reaction • Always placed to the left of the equation CO2 + H2O  C6H12O6 + O2 Reactants

15. Products • The “end” of the equation • Substances that are made • Always placed to the right of the equation CO2 + H2O  C6H12O6 + O2 Products

16. Law of Conservation of Mass • States that mass cannot be created or destroyed • In every chemical reaction, the mass of the reactants have to equal the mass of the products

17. Balance Chemical Equations • Balance chemical equation shows the law of conservation of mass • The number of atoms on each side of the arrow have to be equal to each other Equation is balanced and supports the law