1. Topics Subatomic Particles, their Mass & Electric Charge Protons Neutrons Electrons Atomic Number Isotopes Atomic Mass Molar Mass Average Atomic Mass Calculating Average Atomic Mass

2. What are the Pieces of an Atom? Protons Neutrons Electrons

3. How do they compare? (Mass) Proton Mass = 1.7 x 10 -27 kg Neutrons Mass = 1.7 x 10 -27 kg Electrons Mass = 9.1 x 10 -31 kg

4. How do they compare? (Mass) Proton Mass = 1.7 x 10 -27 kg Neutrons Mass = 1.7 x 10 -27 kg Electrons Mass = 9.1 x 10 -31 kg Look at how these number compare

5. How do they compare? (Mass) Proton Mass = 1.7 x 10 -27 kg Neutrons Mass = 1.7 x 10 -27 kg Electrons Mass = 9.1 x 10 -31 kg Look at how these number compare

6. How do they compare? (Mass) ProtonNeutronElectron Grape If an electron is like a grape, which fruit can represent a proton/neutron?

7. How do they compare? (Mass) ProtonNeutronElectron Grape If an electron is like a grape, which fruit can represent a proton/neutron?

8. How do they compare? (Mass) ProtonNeutronElectron Watermelon Grape

9. How do they compare? (Mass) ProtonNeutronElectron 1.7 x 10 -27 kg 9.1 x 10 -31 kg Watermelon Grape

10. How do they compare? (Electric Charge) Neutrons Charge = ? Proton Charge = ? Electrons Charge = ?

11. How do they compare? (Electric Charge) Neutrons Charge = 0 (Neutral) Proton Charge = +1 Electrons Charge = -1 Protons & Electrons have opposite charge

12. How do they compare? ProtonNeutronElectron 1.7 x 10 -27 kg 9.1 x 10 -31 kg Watermelon Grape + 1 = Positive0 = Neutral-1 = Negative

13. How do they compare? (Location) Neutrons are Protons are Electrons are

14. How do they compare? (Location) Neutrons are in the Nucleus Protons are in the Nucleus Electrons are outside the Nucleus

15. How do they compare? (Location) Neutrons are in the Nucleus Protons are in the Nucleus Electrons are outside the Nucleus

16. How do they compare? ProtonNeutronElectron 1.7 x 10 -27 kg 9.1 x 10 -31 kg Watermelon Grape + 1 = Positive0 = Neutral-1 = Negative In Nucleus Outside Nucleus

17. What determines the identity (element) for an atom? # or protons What is the number of protons called? The Atomic Number The Atomic Number is listed on the Periodic Table

18. What determines the identity (element) for an atom? # or protons What is the number of protons called? The Atomic Number The Atomic Number is listed on the Periodic Table

19. What is an Isotope? Atoms of the same Element With differing numbers of Neutrons

20. What is an Isotope? Atoms of the same Element With differing numbers of Neutrons What is different about the two Helium Isotopes? What is the same for the two Helium Isotopes?

21. What is an Isotope? Atoms of the same Element With differing numbers of Neutrons What is different about the two Helium Isotopes? The number of Neutrons (shown in Yellow) What is the same for the two Helium Isotopes? The number of electrons and the number of protons.

22. What is an Isotope? What are the symbols for this Isotopes?

24. Try this one:

26. What makes an Isotope Stable. For the answer to this visit the https://phet.colorado.edu/en/simulation/build-an-atomhttps://phet.colorado.edu/en/simulation/build-an-atom Or to a Search for: phet Build and Atom

27. Nature does not make all Isotopes in equal amounts. Below are examples of the Isotopes of Boron, Carbon and Nitrogen and the Mass Numbers with their abundance illustrated in the graph. Which Isotope of Carbon is most Abundant? About what percentage of Carbon atoms are C-13?

28. If not all Atoms of an Element are the same Mass, what mass should be assigned to that element? If not all people have the same height, what height should be assigned to represent all people?

29. A weighted Average is used: A weighted Average gives more influence to the more abundant Isotopes A weighted Average gives less influence to less abundant Isotopes.

32. The Average Atomic Mass is given on the Periodic Table for each element. This number represents several things: Average Atomic Mass – mass of a single atom Molar Mass – mass of 6.02 x 10 23 atoms Relative Mass – Mass compared with a Hydrogen Atom