1.  Intro to the Atomic Theory Elements, Atoms, and Subatomic Particles Bill Nye - Atoms

2. Matter  What is matter?  It is the substance that all objects are made up of  What is matter made up of?  Atoms – these are the smallest particle of any element

3. Atoms  What are atoms made up of?  Subatomic particles  What are subatomic particles?  Particles that are smaller than the atom/  Parts that make up the atom

4. Subatomic Particles  What are the 3 types of subatomic particles?  Protons  Neutrons  Electrons

5. Protons  Represented as: p+  Have a +1 electrical charge  “Positive Protons”  Have a relative mass of ~ 1 amu (atomic mass unit)  Located in the atom’s nucleus

6. Neutrons  Represented as: n  Has no electrical charge  “No charge neutrons”  Has a relative mass of ~ 1 amu (atomic mass unit)  Is located in the atom’s nucleus

7. Electrons  Represented as: e-  Has a -1 electrical charge  ‘egative electrons  Has a relative mass of ~ 1/2000 amu (atomic mass units)  It is located in the region around the nucleus

8. Comparing the 3 Subatomic Particles SymbolElectrical Charge Relative Mass Location in the Atom What it accounts for Protonsp++11NucleusMass of the atom Neutronsn01NucleusMass of the atom Electronse-1/2000Around the nucleus Volume of the atom

9. Anatomy of an Atom NEUCLEUS = center of the atom; contains the PROTONS and NEUTRONS ELECTRONS = moving around the nucleus in organized energy levels

10. Atomic Number and Mass  Atomic Number = the number of p+ found in the nucleus  This number never changes  Atomic Mass = the number of p+ and n found in the nucleus  So the number of neutrons is the atomic mass - the atomic number

11. Neutral Atoms  There are the same number of p+ in an atom as e-  Protons give the atom a positive charge  Electrons give the atom a negative charge  Together, these two charges cancel each other out, making the atom neutrally charged Example: Potassium (K) has an atomic number of 19. That means there are 19 protons in the nucleus. That means there are also 19 electrons in the atom.

12. Practice!  For Boron:  What is the atomic number?  What is the atomic mass?  How many protons are in the atom?  How many neutrons are in the atom?  How many electrons are in the atom? 12 5 10.81 5 Round to the nearest whole # 11 – 5 = 6 5

13. Practice!  For Silicon:  What is the atomic number?  What is the atomic mass?  How many protons are in the atom?  How many neutrons are in the atom?  How many electrons are in the atom? 13 14 28.086 14 28.086 Round to the nearest whole # 28 – 14 = 14 14

14. Nuclear Charge  Nuclear Charge = the electrical charge on the nucleus  Since the protons are the only subatomic particle in the nucleus with a charge, the nuclear charge = the number of protons  Atomic # = # of p+ = nuclear charge The atomic number for Carbon is 6. That means there are 6 protons in the nucleus. That also mean that the nuclear charge is +6. What are the nuclear charges on the rest of these elements?

15. Review  What are the charges on the subatomic particles?  What particle(s) account for the atom’s mass?  What particle(s) account for the atom’s volume?  What is a neutral atom? Homework  Read pg. 170-171  Complete the Atomic Structure WS 15 Protons positive Electrons negative Neutrons neutral Protons and Neutrons Electrons Protons = Electrons