3.  Determines the element  Number of protons CANNOT change for an element  Common charge notation is +1  Mass (g) = 1.673 x 10 -24  Mass (amu)= 1.0073 = 1

4.  Common charge notation is 0. No charge!  Mass (g) 1.675 x 10 -24 (same mass as proton)  Mass (amu)= 1.0082 = 1  Number of neutrons CAN change for an element  ISOTOPES  Stabilizes nucleus by nuclear force

5.  Common Charge notation is -1  Mass (g) of e- = 9.109 x 10 -28  Mass (amu)=.0006 = 0  Number of electrons CAN change for an element  ISOTOPES  Responsible for chemical reactivity, forms bonds

6. ProtonNeutronElectron LocationNucleus Outside of nucleus Common charge+0_ Mass, g1.673x10 -24 1.675 x 10 -24 9.109 x 10 -24 Atomic mass unit, amu 1.0073 1 1.0082 1.0006 0

7.  Which subatomic particle can NOT change for an element and gives its identity?

8.  Atomic Number: The number of protons in each atom of that element.  The atomic number is located above the element symbol.  Unique to EACH element, never changes!!

9.  Isotopes: Are atoms of the same element that have different masses.  An Isotope of an element has different number of neutrons. Example of isotopes:

10. Mass Number: The total number of protons and neutrons that make up the nucleus of an isotope. Common isotopes of carbon Carbon-12 Carbon-13 Carbon-14 *12, 13, and 14 are mass numbers*

11.  Element- Mass number

12.  Ions :are when the electron number and proton number are different leading to a net charge.  NOTE: YOU WILL ALWAYS ASSUME ATOMS ARE NEUTRAL (protons = electrons) UNLESS TOLD OTHERWISE

13.  Atomic #= Proton #= Electron # (because we assume atoms are neutral)  Mass #= Atomic # + Neutron #

14.  Number of protons= Atomic number  Number of electrons = Number of protons (in a neutral atom)  Number of neutrons = Mass number– Atomic number SymbolAtomic # Mass ## of protons # of electrons # of neutrons Na11 1531

15.  Average atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of an element  This number appears below the element symbol on the periodic table.