Section 3.1 – The Elements

1. Section 3.1 – The Elements Period: 5 Group 7

2. Background

3. Introduction to the Elements • 4 fundamental elements – fire, earth, water, and air from Greece • Alchemists discovered elements & their characteristics • Several “Fake” alchemists tried to change metals to gold but failed and learned how to prepare acids • Materials on earth & universe → ~ 100 different elements • Building blocks of all other substances

4. Example 1 Question: Why did the “fake” alchemists can’t change metals into gold? Solution: Because metal is not gold but it is a category for all the elements that are present in the state of metal.

5. “Father of Modern Chemistry”

6. Chemistry Explorers – Robert Boyle (1627-1691) • Considered “Father of Modern Chemistry” • Pioneering work on the properties of gas • Science should be firmly grounded on experiments • His experimental definition of an element was accepted → proved air is not an element → Greek system of four elements died

7. Example 2 Question: How did Robert Boyle disapprove the Greek system of four elements? Solution: Because he used experiments to define the meaning of element thus proved that air, water, earth, and fire couldn’t be elements.

8. 115 elements with 88 natural elements and 27 made-in-labs elements Elements vary greatly in abundance 9 elements account for most of the compounds in earth’s crust Elements found in living matter is very different from the ones found in earth’s crust Abundances of Elements

9. Abundances of Elements

10. Example 3 Question: What is the difference between the elements in the earth’s crust and in the human body? Solution: The difference is the elements found in the human body are crucial for life while the ones found in earth’s crust made up everything around us.

11. Names and Symbols for the Elements • Names come from many sources • Reflects the place of discovery • Named in honor of famous scientists or its properties • Abbreviations to simplify the written word • Chemists use element symbols to name the elements

12. Names and Symbols for the Elements

13. Example 4 Question: How are symbols for elements given on the periodic table? Solution: They are named after famous scientists, places they were discovered, or are based on t he Greek language.

14. Essential to human body Helps the functioning of thyroid gland or mains proper calcium levels Involved in metabolism of sugars or production of red blood cells Affects our health and behaviors Trace Elements

15. Trace Elements

16. Trace Elements

17. Example 5? Question: How are elements such as calcium, carbon, nitrogen, and iron essential to our lives? Solution: They help the human body to function and keep us healthy and strong.

18. Quiz • How do we make compounds or molecules? • Why is air not an element? • How many forms of elements are there and explain them? • What are element symbols for and give an example? • How do elements affect our environment and behaviors?

19. Answer Key • By putting together different elements because they will form ionic, covalent, or metallic bonds from sharing the electrons. • Because air is a substance that can be broken down into one or more simpler substances • There are 3 forms of elements: microscopic – single atom of that element, macroscopic – sample of element large enough to weigh on a balance, and generic – elements are present in some form in the human body. 4. Element symbols are used to abbreviate or shorten the elements’ names and an example would be phosphorus with the symbol P. 5. Elements affect our environment and behaviors because they appeared in our everyday surroundings and studies have shown that elements in the hair do affect our behaviors.

20. References • Charts and Pictures in Chemistry Textbook • http://rst.gsfc.nasa.gov/Sect20/ElementShells.JPG • http://upload.wikimedia.org/wikipedia/commons/a/aa/Periodic_table.gif • http://www.particleadventure.org/images/page-elements/4-elements.jpg • http://www.leeds.ac.uk/library/adopt-a-book/pics/boyle.jpg • http://serc.carleton.edu/images/NAGTWorkshops/health04/ChyiPoster1Image.gif • http://www.scientific-web.com/en/Physics/Biographies/images/RobertBoyle2.jpg • http://www.ganeshaspeaks.com/blogImages/gold1%2001_24022009.jpg