Elements_ Ions_ and Isotopes by hcj

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									    Technical Science
Introduction to Chemistry

  Elements, Isotopes, & Ions
Elements, Isotopes, & Ions
 In this section you will…
   – Review the Model of the Atom
   – Describe the Properties of the Proton
   – Describe the Properties of the Neutron
   – Describe the Properties of the Electron
                                                  1 of 4
Review the Model
                                                  Home
of the Atom
 In the previous tutorial “The Atom”, you made a
  model of the atom.
 You also explored the properties of the three
  subatomic particles.
 Complete the following slides
  to summarize the structure
  of the atom and the properties
  of the subatomic particles
                                               2 of 4
Review the Model
of the Atom
 Atoms are composed of 3 subatomic particles.
 The protons and neutrons are located in a small area
  in the the center of the atom called the nucleus.
 Electrons move around the nucleus in much the
  same way planes circle an airport waiting to land.


   Proton
                                           Nucleus
   Neutron
   Electron
                                                            3 of 4
Review the Model
of the Atom
 Summarize the Model of the Atom

         ? Record the locationofeach particles.
            Record the mass
             Record three subatomic particle.
                                  the
         ? ?Name thethechargeofofeachparticle.



    Subatomic      Mass         Charge       Location
     Particle
      Proton      1 AMU           +1          Nucleus

     Neutron      1 AMU            0          Nucleus
                                            Energy Levels
     Electron     0 AMU           -1         & Orbitals
                                               4 of 4
Review the Model
                                               Home
of the Atom
 Our model of the atom is a representation of the
  most current information about atoms.
 It places the protons and neutrons in a small dense
  nucleus in the center with the electrons moving
  around the outside.
 In the following sections you will explore each
  of the subatomic particles in more
  detail and learn how each
  contributes to the properties of
  the atom.
                                                1 of 6
Describe the Properties
                                                Home
of the Proton
Proton
     Subatomic
                  Mass     Charge    Location
      Particle

         Proton   1 AMU      +1       Nucleus


 There are approximately 109 different types of
  atoms. 88 occur naturally. 21 are man-made.
 An element is a pure substance composed entirely
  of one type of atom.
 Protons are the most important subatomic particle
  because they determine the type of atom.
                                               2 of 6
Describe the Properties
of the Proton
Proton
 The numbers of protons in the first 8 elements are
  listed below.
                                   Element # Protons
 The number of protons           Hydrogen     1
  determine the type of atom.     Helium       2
 In other words, if an atom has Lithium       3
  8 protons, it must be an        Beryllium    4
  oxygen atom.                    Boron        5
 If an atom is oxygen, it must   Carbon       6
  have 8 protons.                 Nitrogen     7
                                  Oxygen       8
                                                 3 of 6
Describe the Properties
of the Proton
Proton
 Because of the important role the protons play in
  determining the element …
                                  Element # Protons
 The number of protons          Hydrogen     1
  in an atom is called the       Helium       2
  Atomic Number.                 Lithium      3
 Oxygen has 8 protons          Beryllium    4
  therefore it has an           Boron        5
  atomic number of 8.           Carbon       6
                                Nitrogen     7
                                Oxygen       8
                                             4 of 6
Describe the Properties
of the Proton
Proton
 Complete the table below?
             Element    # Protons   Atomic
                                    Number
            Hydrogen       1           1
            Helium         2          2
            Lithium        3          3
            Beryllium      4          4
            Boron          5          5
            Carbon         6          6
            Nitrogen       7          7
            Oxygen         8          8
                                                5 of 6
Describe the Properties
of the Proton
Proton
 What is the only element that   Element     Atomic
  has atoms with 3 protons?                   Number

 Lithium: A lithium atom         Hydrogen      1

  always has 3 protons. It has    Helium        2
  an atomic number of 3.          Lithium       3
                                  Beryllium     4
 How many protons will an        Boron         5
  atom of Boron always have?      Carbon        6

 Five: It has an atomic number   Nitrogen      7
                                  Oxygen        8
  of 5 therefore there are 5
  protons.
                                               6 of 6
Describe the Properties
                                               Home
of the Proton
Proton - Review
 Protons have a mass of 1 AMU, a +1 charge, and
  are located in the nucleus.
 The positively charged protons make the nucleus of
  the atom positive as well.
 The number of protons in an atom is also called the
  atomic number.
 It is the number of protons in a atom that determine
  the type of element.
                                                  1 of 13
Describe the Properties
                                                  Home
of the Neutron
Neutron
     Subatomic
                  Mass      Charge     Location
      Particle

      Neutron     1 AMU        0       Nucleus


 Neutrons, like protons, are located in the nucleus
  and have a mass of 1 AMU.
 Neutrons, unlike protons, have no charge.
 Since neutrons have no charge, the nucleus of an
  atom will always have a positive charge that results
  from the protons.
                                              2 of 13
Describe the Properties
of the Neutron
Neutron
 Neutrons and protons are the only particles that
  have mass and they are located in the nucleus.
 Therefore, the mass of an atom is determined by the
  number of protons and neutrons and …
 The mass is concentrated in the nucleus.

        Atomic Mass = Protons + Neutrons
                                              3 of 13
Describe the Properties
of the Neutron
Neutron
 Complete the table given the atomic number and the
  atomic mass of the atom.

  Atomic         Atom        # Protons   # Neutrons
  Number           2
                 Helium          2           2
  Atomic           4
   Mass             3
                 Lithium         3           4
                    7
                   11
                 Sodium          11          12
                   23
                                                  4 of 13
Describe the Properties
of the Neutron
Neutron
 The atomic number (# of protons) determines the
  type of atom (element).
 An atom with 2 protons is helium. A helium atom
  will always have 2 protons.
                      2 Protons    Atomic Number = 2
                      2 Neutrons   Atomic Mass = 4

                       Elements tend to have a “usual”
                    number of neutrons. For example, most
                       helium atoms have 2 neutrons.
       Helium
                                             5 of 13
Describe the Properties
of the Neutron
Neutron
 What if two atoms have the same number of protons
  but a different number of neutrons?

                      Protons
                      2    2

                      Neutrons
                      2     1

  Atomic Number = 2               Atomic Number = 2
    Atomic Mass = 4                Atomic Mass = 3
                                               6 of 13
Describe the Properties
of the Neutron
Neutron
 Since both atoms have the same atomic number
  they are the same element; Helium in this case.
 Both atoms are helium yet their mass is different
  because they have a different number of neutrons.
Helium                                        Helium




         Atomic Number = 2     Atomic Number = 2
          Atomic Mass = 4       Atomic Mass = 3
                                                7 of 13
Describe the Properties
of the Neutron
Neutron
 Atoms that have the same number of protons but a
  different number of neutrons are called Isotopes.
 Isotopes are identified by including their mass along
  with their name.
Helium - 4                                     Helium - 3




        Atomic Number = 2       Atomic Number = 2
         Atomic Mass = 4         Atomic Mass = 3
                                               8 of 13
Describe the Properties
of the Neutron
Neutron
 Although both atoms represent different forms of
  helium, the term isotope is usually used when
  referring to the unusual form of the element.
 The atom on the right is the unusual form so it
  would be called Helium-3 isotope. The common
  form on the left is usually just called Helium.
     Helium - 4                         Helium - 3
                                               9 of 13
Describe the Properties
of the Neutron
Neutron
 The table below shows some elements with their
  atomic number (top) and their “usual” atomic mass.
         1           7         8        11
      Hydrogen   Nitrogen   Oxygen    Sodium
         1          14        16        23

 How many protons and neutrons are in the isotope
  Nitrogen-15.
 7 protons and 8 neutrons. If an element is nitrogen
  it must have 7 protons. The 15 refers to the mass.
  If 7 are protons then there must be 8 neutrons.
                                               10 of 13
Describe the Properties
of the Neutron
Neutron
 The table below shows some elements with their
  atomic number (top) and their “usual” atomic mass.
         1           7         8        11
      Hydrogen   Nitrogen   Oxygen    Sodium
         1          14        16        23

 How many protons and neutrons are in the isotope
  Hydrogen-3.
 1 proton and 2 neutrons. If an element is hydrogen
  it must have 1 proton. The 3 refers to the mass. If
  there is 1 proton then there must be 2 neutrons.
                                               11 of 13
Describe the Properties
of the Neutron
Neutron
 The table below shows some elements with their
  atomic number (top) and their “usual” atomic mass.
         1           7         8        11
      Hydrogen   Nitrogen   Oxygen    Sodium
         1          14        16        23

 What would you call an atom with 8 protons and
  9 neutrons.
 Oxygen-17. If an atom has 8 protons, it must be
  oxygen. The additional 9 neutrons gives it a mass
  of 17 making it an oxygen-17 isotope.
                                              12 of 13
Describe the Properties
of the Neutron
Neutron
 The table below shows some elements with their
  atomic number (top) and their “usual” atomic mass.
         1           7         8       11
      Hydrogen   Nitrogen   Oxygen   Sodium
         1          14        16       23

 What would you call an atom with 11 protons and
  11 neutrons.
 Sodium-22. If an atom has 11 protons, it must be
  sodium. The additional 11 neutrons gives it a mass
  of 22 making it a sodium-22 isotope.
                                            13 of 13
Describe the Properties
                                             Home
of the Neutron
Neutron - Review
 Neutrons have a mass of 1 AMU, no charge, and
  are located in the nucleus.
 Neutrons along with protons determine the atomic
  mass of the atom.
 Two or more atoms may have the same number of
  protons but a different number of neutrons. This
  means that they are the same element but they have
  a different mass.
 These different forms of the same element are
  called isotopes.
                                                    1 of 16
Describe the Properties
                                                    Home
of the Electron
Electron
     Subatomic
                  Mass      Charge    Location
      Particle
                                     Energy Level
      Electron   0 AMU        -1
                                      / Orbitals


 Electrons are located in the energy levels and
  orbitals.
 Electrons have a negative one (-1) charge.
 Electrons stay in “orbit” around the nucleus because
  they are negatively charged and the nucleus is
  positively charged. Opposite charges attract.
                                                    2 of 16
Describe the Properties
of the Electron
Electron
 The number of electrons in an atom is equal to the
  number of protons before an atom reacts.
 The atomic number of an atom identifies both the
  number of protons and the number of electrons in
  an unreacted atom.
                           2 Protons     Atomic Number = 2
                           2 Electrons




           Helium
                                                   3 of 16
Describe the Properties
of the Electron
Electron
 Complete the table below.

         Element    Atomic      #          #
                    Number   Protons   Electrons
        Hydrogen      1        1           1
        Helium        2        2           2
        Lithium       3        3          3
        Beryllium     4        4          4
        Boron         5        5          5
        Carbon        6        6          6
                                              4 of 16
Describe the Properties
of the Electron
Electron
 In an unreacted atom the number of protons is equal
  to the number of electrons. How does this
  relationship effect the whole atom?
 Protons (+1) & electrons (–1) have opposite charges.
 Opposite charges not only attract but they cancel
  each other out. 5 positive charges can cancel out 5
  negative charges. So…
 In an unreacted atom where the number of protons
  equals the number of electrons the overall charge on
  the atom will be zero.
                                                        5 of 16
Describe the Properties
of the Electron
Electron
 Complete the table below for the unreacted atoms.

    Element    Atomic      #          #       Overall
               Number   Protons   Electrons   Charge
   Hydrogen      1        1          1          0
   Helium        2        2          2          0
   Lithium       3        3          3          0
   Beryllium     4        4          4          0
   Boron         5        5          5          0
   Carbon        6        6          6          0
                                                6 of 16
Describe the Properties
of the Electron
Electron
 Although the number of protons and electrons in an
  atom start out equal they don’t stay that way.
 When an atom reacts it gains or loses electrons.
 If an atom gains or loses electrons its overall charge
  will no longer be zero.
 An atom will become negatively charged if it gains
  electrons. It will become positively charged if it
  loses electrons.
 An atom that has a positive or negative charge
  because it gained or lost electrons is called an Ion.
                                                            7 of 16
 Describe the Properties
 of the Electron
Electron
 Watch what happens to the lithium atom when it
  reacts and loses an electron.
    Overall Charge                           3 Protons in the nucleus
in the Unreacted Atom                              + 3 Charge
       Zero
                                                   3 Electrons
                                                   2
Atom Loses 1 Electron                                2
                                                   - 3 Charge

   Overall Charge
  After the Reaction
         +1                   Lithium
                         Lithium Ion (+ 1)
                        Atomic Number = 3
                                                             8 of 16
 Describe the Properties
 of the Electron
Electron
 Watch what happens to the fluorine atom when it
  reacts and gains an electron.
    Overall Charge                            9 Protons in the nucleus
in the Unreacted Atom                               + 9 Charge
       Zero
                                                    9 Electrons
                                                   10 Electrons
Atom Gains 1 Electron                                 9 Charge
                                                   --10 Charge
   Overall Charge
  After the Reaction
         -1                 Fluorine
                         Fluorine Ion (- 1)
                        Atomic Number = 9
                                              9 of 16
Describe the Properties
of the Electron
Electron
 What do you think would happen to an atom if it
  Lost 2 electrons?
 The atom would have two more protons than
  electrons so it would become an ion with a +2
  charge.
 What do you think would happen to an atom if it
  Gained 2 electrons?
 The atom would have two more electrons than
  protons so it would become an ion with a -2 charge.
                                                10 of 16
Describe the Properties
of the Electron
Electron
 You know what happens when an atom gains or
  loses an electron. But, why does an atom react in
  the first place?
 An atom reacts (gains or loses electrons) to fill the
  S and P orbitals or its outermost energy level.
 Review the structure of the energy levels and
  orbitals on the next slide.
                                                11 of 16
Describe the Properties
of the Electron
Electron - Energy Levels and Orbitals


Nucleus

Level 1                             S

Level 2                     S   P       P   P

Level 3             S   P   P   P D D D D D

Level 4   S P   P   P D D D D D F F F F F F F
                                                 12 of 16
Describe the Properties
of the Electron
Electron
 Energy Levels determine an electron’s distance
  from the nucleus.
 Orbitals are subdivisions of energy levels and they
  determine the position of an electron within an
  energy level. (2 electrons can fit in each orbital.)
 Remember, atoms will gain or lose electrons
  (react) to fill the S and P orbitals of their outermost
  energy level.
                                                              13 of 16
Describe the Properties
of the Electron
 What will Lithium (atomic # 3) do when it reacts?
                      AnIt will be starts out with 3 &tofill the
                          Lithiumgoalgain7 fill the S unless it 1
                           atom can’t is for LithiumtoP lose can
                     Lithium could gaintoelectrons electrons. 2nd
                           atom’s easier electrons          orbitals
                      find2anotherenergy & 1to gain 7. are two
                             in the that will lose 1 electron.
                                  electron than in An nd
                     energy level or it couldgive.the 2atom can’t
                        of its outer1st level level. There levelThis
       3P            lose ways lithium1st 1 electron it will take on
                     When Lithium loses level the outer level and
                           electrons unless it accomplish this.
                      would make the couldcan find another that
                                the 1st and Therefore…
                                  will level is already full.
                         a +1 charge take.become a lithium ion.

 Lithium Ion (+1)
     Nucleus                            *
     Level 1                            S
     Level 2                        S P P P
     Level 3                S P P P D D D D D
     Level 4        S P P P D D D D D F F F F F F F
                                                               14 of 16
Describe the Properties
of the Electron
 What will Fluorine (atomic # 9) do when it reacts?
                          Fluorinecan’t gain fillelectronto gainthe
                           Itatombegoal is for 1with 9 & to orbitals
                             atom’scould gain Fluorine P fill can
                                       starts out the S unless it
                        AnFluorineeasier toelectrons electrons.1
                              will
                        findits outerlevel or & give.lose 2atom two
                               in the that will 7 to An nd electrons.
                      third2anotherenergy it couldThere are can’t
                          of energy 1st level level. the 7.7 level
                                    electron than in lose
       9P               When Fluorine gains st electron it will level
                             would make could level the outer
                       Thiselectrons unless 1can find anothertake
                       loseways fluorine theit 1 accomplish this.that
                               and will 1and Therefore… full.
                        on a -1 chargetake. become a Fluorine ion.
                                    the st level is already

 Fluorine Ion (-1)
     Nucleus                             *
     Level 1                             S
     Level 2                         S P P P
     Level 3                 S P P P D D D D D
     Level 4         S P P P D D D D D F F F F F F F
                                               15 of 16
Describe the Properties
of the Electron
 In the previous examples, Lithium lost 1 electron
  and became a lithium ion (+1). Fluorine gained 1
  electron and became a fluorine ion (-1).
  Why are these atoms still considered to be lithium
  and fluorine even after they react?
 When these atoms reacted they gained or lost
  electrons. But remember, it’s not the electrons that
  determine the element, it’s the protons. The
  protons didn’t change. Lithium remains lithium
  because it still has 3 protons. We call it an ion to
  show that it has reacted and taken on a charge.
                                             16 of 16
Describe the Properties
                                               Home
of the Electron
Electron - Review
 In an unreacted atom the number of protons equals
  the number of electrons
 Unreacted atoms have an overall charge of zero.
 When an atom gains or loses electrons it takes on a
  charge and becomes an ion.
 An atom that gains electrons is negatively charged.
  An atom that loses electrons is positively charged.
 Atoms gain or lose electrons to fill the S & P
  orbitals of their outer energy level.
    Technical Science
Introduction to Chemistry

     You have Completed
  Elements, Isotopes, & Ions

                Created by John W. Pluemer

								
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