TOPIC. Chemical Formulas. Essential Question: What is the law of conservation of mass, and how does it apply to chemical equations?

Transcription

1 TPIC Chemical Formulas Essential Question: What is the law of conservation of mass, and how

2 Chemical formulas are written using an element s chemical symbol from the periodic table. They are used to identify how many atoms of each element are present.

3 Chemical formula for water 2 0 Subscript- tells you how many atoms per element there are ne molecule of water contains 2 ydrogen atoms and 1 xygen atom.

4 Chemical formula for water Coefficient- tells you how many molecules there are There are 3 molecules of water

5 Chemical formula for water Coefficient- you multiply the coefficient by the subscript to get the number of atoms per element There are 6 hydrogen atoms and 3 oxygen atoms

6 Law of conservation of mass During a chemical reaction, no matter is created or destroyed, it is just rearranged The chemical equation is balanced

7 ow to see if a chemical equation is balanced ) Take an element inventory for each side of the equation 2.) Write down the number of atoms for each element 3.) If the numbers match, then it is balanced 2

8 Now take some time Take 2 minutes to go over your notes and highlight or underline the main ideas that answer the essential question, you should not highlight everything: Essential Question: What is the law of conservation of mass, and how does it apply to chemical equations?

9 Time to use the left hand column You will be writing your own questions from now on! To get you started, verbs will be provided

10 Choose one verb to write your question: Chemical formulas Are written using an elements chemical symbol from the periodic table Define Describe Compare Explain Used to identify how many atoms of each element are present

11 Choose one verb to write your question: Define Describe Compare Explain Chemical formula for water 2 0 Subscript- tells you how many atoms per element there are There are 2 ydrogen atoms and 1 xygen atom in water

12 Choose one verb to write your question: Define Describe Compare Explain Chemical formula for water Coefficient- tells you how many molecules there are There are 3 molecules of water

13 Choose one verb to write your question: Define Describe Compare Explain Chemical formula for water Coefficient- you multiply the coefficient by the subscript to get the number of atoms per element There are 6 hydrogen atoms and 3 oxygen atoms

14 Law of conservation of mass Choose one verb to write your question: Define Describe Compare Explain During a chemical reaction, no matter is created or destroyed, it is just rearranged The chemical equation is balanced

15 Choose one verb to write your question: Define Describe Compare Explain ow to see if a chemical equation is balanced ) Take an element inventory for each side of the equation 2.) Write down the number of atoms for each element 3.) If the numbers match, then it is balanced 4 2

16 Time to use the left hand column You will now write questions on your own using question starters that are provided

17 Now let s write a summary Look at each question you wrote on your own, and answer each question in a complete sentence.