1. CHEMICAL INTERACTIONS G8 NY, SP and TA – 2011 Mr. ARNOLD, Rafael

2. What is Chemistry? chem·is·try definition Pronunciation: /ˈkem-ə-strē/ Function: n pl tries ; 1 : a science that deals with the composition, structure,and properties of substances and of the transformations that theyundergo 2 a : the composition and chemical properties of a substance/the chemistry of hemoglobin b : chemical processes and phenomena (as of an organism)/blood chemistry Merriam-Webster's Medical Dictionary, © 2007 Merriam-Webster, Inc.

3. Atoms are the smallest form of elements EXPLORE: The Size of Atoms (Page 9) It takes about 31 cuts to get to the size of an atom!

4. History Greek Phylosophers ~300 BC – 4 elements: air, water, fire and earth. Today – ~100 basic elements

5. Names and Symbols of the Elements Tribute to people or places; Translation of words in Greek or Latin. It can be the first letter of the name ( always capitalized ): Hydrogen (H) Sulfur (S) Carbon (C) Or the first and another one ( only the first letter is capitalized ): Aluminum (Al) Platinum (Pt) Cadmium (Cd) Zinc (Zn)

6. What is the difference between atoms and molecules?

7. Types of atoms in Earth’s crust and living things

8. Each element is made up of a different atom How can they be different?

9. Experiment: Electrical Charges

10. What can you conclude from the experiments performed?

11. The Structure of an Atom

13. Atomic Number Atomic number is the number of protons present in the nucleus; Each element has a specific atomic number, this allows the existence of a great variety of elements.

14. Atomic Number

15. Atomic Mass Number The total number of Protons + Neutrons – Gold: 79 protons + 79 neutrons = Mass Number

16. EXERCISE Using the periodic table, determine the number of neutrons of the following elements: – Al, Cu, Po, Ar, Mn, Zr, Ca, Ti, Md and Fr

17. Isotopes Isotopes are atoms of the same element that have a different number of neutrons Chlorine-35Chlorine-37 Mass number = 35Mass number = 37 Protons = 17 Neutrons = ?

18. Atoms form ions Atoms can interact and even bons to other atoms. An ion is formed when an atom loses or gains one or more electrons.