2.  Fundamental Particle Definitions 1.Matter – anything that takes up space and has mass 2.Atom – smallest whole particle known to man 3.Element – any substance that can not be broken down into other substances by chemical reactions 4.Compound – two or more elements that have combined in a fixed ratio 5.Trace element – elements in minute quantities

3. 6.Neutrons – a subatomic particle with a neutral charge 7.Protons – a subatomic particle which has a positive charge 8.Electrons – a subatomic particle that has a negative charge 9.Dalton – a unit of measurement for neutrons and protons (1.7 x 10 -24 ) 10.Atomic number – the number of protons in the nucleus 11.Atomic weight – the total atomic mass of an element 12.Isotope – an atom that varies its form by changing the number of neutrons in the element

4. 13.Energy – the ability to do work 14.Potential energy – stored energy due to position or location 15.Electron shells – the different states of potential energy for electrons in an atom 16.Orbital – the 3d space in which an electron is found 90% of the time, probable location. 17.Valence electrons – the outer most shell of electrons 18.Covalent bonds – atoms that combine by sharing valance electrons

5. 19.Electronegativity – the attraction of an atom for the electrons of a covalent bond 20.Ionic bond – a type of bonding in which one atom strips away an electron from another atom 21.Ion – a charged atom 22.Hydrogen bond – occurs when a hydrogen atom covalently bonded to 1 electronegative atom is also attracted to another electronegative atom 23.Chemical reaction – the making and breaking of chemical bonds 24.Reactants – the starting materials in a chemical reaction 25.Products – the result of a chemical reaction

6. Matter  Matter consists of chemical elements-anything which occupies space and has mass.  Matter is found in two ways; pure-form or compounds  The Greeks first proposed four elements that made matter; earth, air, fire, and water.  Scientists later discovered 92 naturally occurring elements  They can be man-made or naturally occurring  Two or more elements may combine to form compounds  They can be found naturally in three ways called phases; solid, liquid, and gas

7. Earth Air Fire Water

10. Atoms Movie

11. Elements  There are 92 known elements (naturally occurring)  These elements are found on the periodic table of the elements  Some different elements combine together to form compounds  Table salt is a compound made up of sodium and chlorine  It is written using the abbreviation NaCl  Na = Sodium and Cl = chlorine  The 92 elements are found on the periodic table of the elements

12. Symbols for Elements Symbols are letters that represent the elements on the periodic table 1. If only a single letter, it is Capitalized. 2. If two letters, the 1 st is Capitalized and the 2 nd is lower case. Example: Ca not C A

13. Periodic Table of the Elements Check out the initials for Aluminum in this example off of the Periodic Table:

15. Periodic Table of the Elements The number of protons in an atom is listed above each abbreviation. It is called the Atomic Number.

16. Periodic Table of the Elements The number listed underneath the abbreviation is the Atomic Weight.

17. C Hopkins café mighty-good food never closed zundays. C-Carbon Ca-Calcium H-Hydrogen Fe-Iron O-Oxygen Mg-Magnesium P-Phosphorus F-Fluorine K-Potassium Na-Sodium I-Iodine Cl-Chlorine N-Nitrogen Zn-Zinc S-Sulfur

19.  The atom is the smallest unit to have properties of an element  About one million fit onto a period at the end of a sentence  They are comprised of neutrons, protons, and electrons  Neutrons and protons are neatly packed in the nucleus  Neutrons and Protons have almost exactly the same mass  Each one has the mass of ~1.7 x 10 -24 grams  Electrons are 1/2000 the size of + and N  The number of protons unique to an element is the atomic number  The atomic mass is the total of protons and neutrons in the nucleus  Proton = 1.007 Daltons Neutron = 1.009 Daltons

20. Atomic Particles

21. Structure of an Atom Proton Electron (electron cloud) Neutron Mass Number = Protons + Neutrons Atomic Number = Number of protons

22. Isotopes When the number of protons in an atom changes it becomes a different element Atom is electrically neutral when there are more neutrons than protons Atoms of the same element that have a different number of neutrons are called isotopes Ex. C 12 = 6p +6n C 14 = 6p + 8n

24. Ions Electrically charged atoms are called Ions The number of protons is not equal to the number of electrons Ions are attracted to each other when they have opposite charges Ex. Na + + Cl - = NaCl = salt Ex. Na + + F - = Sodium Fluoride for toothpaste

25. Combinations of Atoms

26. Atoms combine by sharing their outermost electrons in their electron clouds When two atoms are combined a molecule is formed

27. Bonds Ionic Bond – Positive and Negative ions combine and electrons are transferred –Ex. NaCl Covalent Bond – Electrons are shared –Ex. H 2 O

29. Name that term….. 1. What is the smallest particle to possess the qualities of an element? 2. Where are + and n found in an atom? 3. How do you know how many electrons are in an atom? 4. What does the atomic number represent? 5. What does the atomic mass represent?