ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O8 COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O816 COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O8168 COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O81688 COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co27 LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co2759 LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb82

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb82207

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

ElementSymbol Atomic Number Atomic Mass # Protons # Electrons # Neutrons OXYGEN O COBALT Co LEAD Pb

 Atomic Number = ______________

 Atomic Number = # protons  Atomic Mass = _______________

 Atomic Number = # protons  Atomic Mass = # protons + # neutrons  Neutrons = __________________

 Atomic Number = # protons  Atomic Mass = # protons + # neutrons  Neutrons = Atomic Mass – # protons

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Review Atomic Number = Protons Atomic Mass = Protons + Neutrons Neutrons = Atomic Mass – Protons

 What is the difference between these 2 atoms?  Are they the same element?

 There can be different types (varieties) of an element  An isotope is a different form of an element but with a different number of neutrons  Same # of protons (same atomic number)

 If the number of neutrons is different, what else is different about the element?  Atomic Mass = protons + neutrons  If the number of neutrons is different, the atomic mass is also different

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Review Atomic Number = Protons Atomic Mass = Protons + Neutrons Neutrons = Atomic Mass – Protons Isotopes Different forms of an element - Element with different # of neutrons - Atomic number is still the same

 Not all elements have isotopes  If isotopes exist, the most common form of the element is the one found on the periodic table

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Review Atomic Number = Protons Atomic Mass = Protons + Neutrons Neutrons = Atomic Mass – Protons Isotopes Different forms of an element - Element with different # of neutrons - Atomic number is still the same - # of proton is the same - Atomic Mass is different - most common form found on periodic table

 Isotopes are abbreviated with the element and the atomic mass  Example: Helium-3 (He-3)  the atomic mass is 3  how many neutrons does it have? Atomic mass – protons 3 – 2 = 1

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Representing Isotopes Element + Atomic Mass EX. Helium-3

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Representing Isotopes Element + Atomic Mass EX. Helium-3 EX 1: Hawkium-10 (Hk) has an atomic number of 5 and a mass number of 10. Examples # protons:

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Representing Isotopes Element + Atomic Mass EX. Helium-3 EX 1: Hawkium-10 (Hk) has an atomic number of 5 and a mass number of 10. Examples # protons: 5 # electrons:

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Representing Isotopes Element + Atomic Mass EX. Helium-3 EX 1: Hawkium-10 (Hk) has an atomic number of 5 and a mass number of 10. Examples # protons: 5 # electrons: 5 # neutrons:

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 Representing Isotopes Element + Atomic Mass EX. Helium-3 EX 1: Hawkium-10 (Hk) has an atomic number of 5 and a mass number of 10. Examples # protons: 5 # electrons: 5 # neutrons: 5

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 EX 2: Hawkium-12 (Hk) has an atomic number of 5 and a mass number of 12. Examples # protons: # electrons: # neutrons:

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 EX 2: Hawkium-12 (Hk) has an atomic number of 5 and a mass number of 12. Examples # protons: 5 # electrons: # neutrons:

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 EX 2: Hawkium-12 (Hk) has an atomic number of 5 and a mass number of 12. Examples # protons: 5 # electrons: 5 # neutrons:

 In an uncharged atom, the number of protons is the same as the number of ____________.  electrons  An uncharged atom has NO charge. Why?  Protons = electrons Isotopes 10/29/08 EX 2: Hawkium-12 (Hk) has an atomic number of 5 and a mass number of 12. Examples # protons: 5 # electrons: 5 # neutrons: 7 How do we know that Hawkium-12 and Hawkium-10 are isotopes? Hawkium-12 and Hawkium-10 are isotopes - same atomic number - different atomic mass  different # neutrons

 Find the following information for Nitrogen-13, Nitrogen-14, and Nitrogen-15  Atomic Number:  Atomic Mass:  # Protons:  # Electrons:  # Neutrons:  Which isotope is the most common form of Nitrogen?