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          My goal with this section is to let you learn chemistry on your own and at your own pace.  If you are taking my class, we will be doing some extra exploring and have some activities that, hopefully, will make it super simple to learn.  I’ll be attaching links to some of those activities, but if you’re the kinda person who can imagine yourself saying… “just tell me what I need to know and get me out of here” – then read on. A great deal of information here comes from and has been adapted from the book Chemistry Concepts and Problems by Clifford Post and Richard Houk. Feel free to email me any questions or suggestions you have to  kim_fleming@hotmail.com with that said… here goes

         

Everything in the world – trees, people, socks, rocks, pizza – everything!!! Is made up of atoms.  The atom is the backbone of chemistry.  To understand how it works to build stuff, we need to understand 3 basic parts that make it up.  They are SUBATOMIC PARTICLES (really super small pieces that build atoms) – Now… don’t you feel smarter just knowing that?  In this lesson we’re going to look at how those pieces are arranged, and then you will be able to understand why the PERIODIC TABLE is set up the way it is.

When you finish this section, you should have gained an understanding of three things:

1.     Atomic Structure

2.     The Periodic Table

3.     Electronic Structure

Specific Objectives:

·        Be able to describe or draw a picture of:

                                                                                      i.      atoms, protons, electrons, neutrons, nucleus, atomic number, shell, subshell, orbital, alkali metal, noble gas, halogen, alkaline earth, period, group, family, oxide, malleable, ductile, metal, nonmetal, metalloid, and Bohr model of an atom

·        Determine the numbers of protons, neutrons, and electrons in a neutral atom when given it’s mass number and atomic number

·        Compare and contrast the three fundamental particles in an atom according to mass and charge

·        Determine the maximum number of electrons any given shell can hold

·        Determine the maximum number of orbitals in any given shell

·        Write the electron configuration for any element

·        Determine what element is presented when given its electron configuration;

·        Use the periodic table to locate different families of elements and determine whether an element is a metal, nonmetal, or metalloid

 

The Atom

  1. An atom, the smallest unit of an element, is made up of 3 main pieces: electrons, protons, and neutrons.  The combination of these particles in an atom is distinct for each element. An atom of the element radon is composed primarily of a specific combination of what three basic particles?

_____________ ______________ and ________________

 

  1. Let’s forget about neutrons for now and think about electrons and protons.  Each atom of the same element has the same combination of protons and electrons.  An atom of the element helium in outer space has (the same, a different)__________________ combination of electrons and protons as that of an atom of helium on earth?

 

  1. Each element has a unique combination of protons and electrons in its atoms.  The combination of electrons and protons in an atom of one element is different from that in an atom of any other element.  Since each element has a know unique number of protons and electrons in its atoms, would it be possible to identify an element if you know the number of protons and electrons in its atoms?_______________

 

  1. Protons are particles with a positive (plus) charge.  Electrons are particles with a negative (minus) charge.  Unless otherwise stated, an atom is assumed to be neutral, with the positive and negative charges being equal.   In any neutral atom, the number of electrons (having a negative charge) is always equal to the number of protons (having a positive charge).

A boron atom contains five protons.  We assume the atom to be neutral.  How many electrons must it have?______________

 

  1. If an atom contains eight electrons.  How many protons does it contain?_____

 

  1. Each element has a unique number of electrons and protons in it’s atoms.  Since the number of electrons in a neutral atom is equal to the number of protons, do you think we can identify an element if we know just the number of protons in it’s atoms? ___________

 

  1. The periodic table is a very useful table describing the atoms of every know element in the universe. This is what the periodic table looks like.

 

 

Each box is a shorthand notation used to represent a neutral atom of an element.  The symbol “C represents a neutral atom of the element carbon.  The symbol “He” represents a neutral atom of the element helium.

The number of protons in an atom is listed above each symbol. (Ignore the number underneath thee symbol for now.)

 

     

 

An atom of carbon has six protons.  How many protons does an atom of helium have? ­­­­­­­­­­­­­­­­­­­­­­­_____________

 

  1. The number of protons in an atom of an element is called its atomic number.  What is the atomic number of the element helium (He) ______________

 

  1. The element zinc (Zn) has an atomic number of 30.  How many protons does an atom of zinc contain?__________________

 

  1. A neutral atom of zinc contains how many electrons?__________________

 

  1. Using the periodic table, determine the number of electrons in a neutral atom of copper (Cu).__________________

 

Bohr Atomic Model

 

  1. A Danish physicist, Niels Bohr, came up with a model that pictured the atom with a nucleus of protons in the center and electrons spinning in an orbit around it. (Similar to the movement of the planets around the sun).  The following Bohr model contains one orbiting electron and a nucleus of one proton.

 

  1. An electron always caries a negative charge.  A proton carries a charge exactly opposite that of the electron.  A proton must therefore have a (negative, positive, neutral) __________________ charge.

 

  1. An electron has very little mass when compared to a proton.  It takes about 1836 electrons to equal the weight of just one proton.  In a hydrogen atom consisting of just one proton and one electron, the greatest proportion by weight is accounted for by the (electron, proton) ________________.

 

  1. The element helium (He), represented by the Bohr model below, has an atomic number of ___________.

 

 

  1.  The neutral atom of He contains how many protons? ______ electrons?______

 

  1. The weight of an atom of helium is not totally accounted for by the protons and electrons.  A third subatomic particle, the neutron, is responsible for the additional weigh.  The neutral atoms of all elements except the most common form of the element hydrogen have one or more neutrons in the nucleus of their atoms.  The diagram below shows the neutrons in the corrected Bohr model of helium.

Since the neutral atom contains equal numbers of negatively charged electrons and positively charged protons, what type of electrical charge do you think is possessed by a neutron? (negative, positive, no charge) _________________

 

  1. A neutron is slightly heavier than a proton.  Of the primary fundamental particles in an atom:

(a)   Which is the lightest in weight? ____________________

(b)   Which is the heaviest? ___________________________

(c)   Which is between the other two in weight? _________

 

  1. In the Bohr model of a lithium atom shown. Which subatomic particle(s) is (are) represented by the circular orbits shown by the larger circles? ______________ Which particle(s) make(s) up the nucleus or center of the atom?_____________________________

 

  1. If the negative charge of an electron is represented by -1, the charge on the proton would be (-1, +1, neutral) __________ and the charge on the neutron would be (-1, +1, neutral __________.

 

  1. Neutrons can be found in all atoms of all elements except the most common form of the simplest element.  Identify that element. (Hint: If you don’t remember, reread frame 17.) ___________

 

You have just learned the names, charges, and relative sizes of the fundamental particles that constitute an atom.  You have also been shown one model representing the arrangement of these particles in an atom.

     We have referred you to the periodic table and hinted that atoms with certain numbers of protons and electrons are located in a specific place in that table.  You learned from your introduction to the periodic table that each atom is identified by some symbol.

     We continue this chapter by looking more closely at the periodic table.  You will be introduced to specific groups of elements and their physical and chemical properties as they relate to their location on the periodic table.  We expand upon the use of symbols and the numbers of each particle in an atom as we prepare to study a second model of an atom.

 

The Periodic Table

 

 

  1. Look at the periodic table.  An atom of each element is represented by a one or two letter symbol such as “C” for carbon and “Al” for aluminum.  These symbols serve as shorthand notation for the elements.  The shorthand symbol in each case indicates a neutral atom.  The symbol “Ca” represents a neutral atom of the element calcium.  Remembering the definition of a neutral atom, you know that Ca contains 20 protons and how many electrons?_____________
    Answer: 20 (A neutral atom contains an equal number of protons and electrons.)

 

  1. The periodic table of the elements is made up of several rows and some columns.  The rows are called periods and the columns are called groups.  The groups are labeled IA, IIA, IIIB, and so on.  The elements Be, Mg, Ca, Sr, Ba, and Ra are included in which group?________________
    Answer: Group IIA

 

  1.  The elements Li, Be, B, C, N, O, F, and Ne are all members of a (group or period)?
    Answer: period

 

  1. Groups are often called families because the elements that make up the groups or families have similar chemical properties.  Argon (Ar) is part of Group VIIIA.  It is a rather unreactive gas.  Since families or groups of elements have similar properties, would you expect Krypton (Kr) to be a highly reactive gas?
    Answer: no (All of the elements in Group VIIIA are rather unreactive.)

 

  1.  Because all Group VIIIA elements are rather unreactive and are gaseous at room temperature, they have been named the noble gas family.  An element in Group VIIIA may be generalized by its family name as a(n) ______________ gas.
    Answer: noble

 

  1. Group IA on the left side of the chart is often called by the family name of alkali metals (with the exception of hydrogen). These elements can react vigorously with water to form strong alkaline solutions  If a friend told you that aluminum (Al) was an alkali metal would he be right or wrong? 
    Answer: wrong (Aluminum is located in Group IIIA and the alkali metals are all located in     Group IA)

 

  1. Group IIA elements are known as the alkaline earth metals because the oxides of these metals (chemical coumpounds of the metals and oxygen) form alkaline solutions in water.  The element potassium (K) can be classified as a(n) (noble gas, alkaline earth, alkali metal) _________________
    Answer: alkali metal (    Group IA)

 

  1. The element Ba(Barium) can be classified as a(n) (alkali metal, alkaline earth, noble gas)___________________________
    Answer: alkaline earth (Group IIA)

 

  1. An unknown element is placed in water.  A vigorous reaction takes place, and the result is an alkaline solution.  Of which family is the element probably a member? (alkaline earth, alkali metal, noble gas)____________________________
    Answer: alkali metal (Alkali metals react directly with water to form alkaline solutions.  The oxides of alkaline earth elements react with water to form alkaline solutions.)

 

  1. The elements in Group VIIA are know as the halogens, which means “salt formers”  Elements from the halogen family combine with metals to form compounds known as salts.  Common table salt (NaCl) is made up of sodium (Na) and chlorine (Cl).  These two elements (Na and Cl) are members of what families or groups?
    Na:_____________________
    Cl:______________________
    Answer:     Group IA, the alkali metals; Group VIIA, the halogens

 

  1. Strontium (Sr) is an element in the _________________ family.  Iodine (I) is an element in the ______________________ family.
    Answer: alkaline earth; halogen

 

 

Metals, Nonmetals, and Metalloids

 

  1. The periodic table can also be divided into just three classes of elements – the metals, the nonmetals, and the metalloids.  In the periodic table, you may have noticed a steplike line,. Elements to the left of this line can be classified as metals (with the exception of hydrogen). A friend informed you that the element Ti(titanium) is a metal.  Is your friend correct?__________-
    Answer: Yes, titanium can be classified as a metal.

 

  1. Certain properties are characteristic of metals.  Metals are usually malleable( can be beaten into fine sheets) and ductile (can be drawn into wires).  Gold leaf is a very thin sheet of gold.  In making gold leaf, we are using what common property of metals?
    Answer: the property of malleability

 

  1. Besides being malleable and ductile, metals are also good conductors of heat and electricity.  Copper is useful in making electrical wiring.  What two metallic properties would be useful in electrical wiring?_________
    Answer: The metal is a conductor of electricity and it is ductile (can be drawn into wires.

 

  1. Metals have a lustrous or shiny surface and are solid at ordinary room temperature (with the exception of mercury, which is liquid at room temperature). Metal cooking utensils take advantage of what tow properties of metal? (conducts electricity, conducts heat, ductile, solid)_______________________
    Answer: Metal conducts heat and is solid.

 

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