Chemistry 2015-2016
Periodic Patterns
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Date:
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Directions: Read the following information. Follow along on your periodic table as you go! Create a key
on your table as you go to remind you of what all the colors mean!
There are somewhere around 110 elements in all—91 of them are found in nature. The rest of the
elements have mostly been created in the laboratory. Even though the entire world, and all its objects,
and all its creatures are made up out of the elements, the average person is probably familiar with only
about 30 of the elements. Some of the elements are very rare or have only existed for very short periods
of time. The element called Einsteinium, number 99, was discovered in the radioactive debris of a
hydrogen bomb test in the Pacific Ocean in 1952.
The elements of the periodic table are organized into two basic groups—metals and nonmetals.
Most of the elements in the entire periodic table are metals. Often there is a stair step line on the periodic
table showing the dividing line between metals and nonmetals.
Nonmetals are poor conductors of heat and electricity. They are located in the upper right hand
portion of the table. They include the eleven elements that are found as gases in their natural state. The
other nonmetals are usually brittle solids. The nonmetals are Carbon, Nitrogen, Oxygen, Phosphorus,
Sulfur, Selenium, and Hydrogen. Color these elements purple.
The metals, on the other hand, are excellent conductors of heat and electricity. They are generally
shiny, malleable (bendable) and ductile (can be drawn out into wires). Most of the elements in the
periodic table are classified as metals. Copper is a typical metal. It is shiny, bends easily, is an excellent
conductor of electricity, and is commonly used for electrical wires. Metals are located on about ¾ or more
of the periodic table—on the left.
Some of the elements do not belong clearly in either classification. These elements are called
metalloids. They have properties of both metals and nonmetals. The metalloids are all located
somewhere along the stair step line between metals and nonmetals. Some periodic tables classify the
metalloids as nonmetals. The following elements are generally considered metalloids: B, Si, Ge, As, Sb, Te,
Po, At. Color the metalloids orange on your periodic table.
The columns in the periodic table are called groups or families. All the groups have similar
properties. We have only included the names of the most significant groups in our periodic table (such as
the alkaline earth metals and the noble gases). There is more than one numbering system for the groups.
Some periodic tables number the groups straight across from 1-18. Some number the groups using a
system of roman numerals and letters.
The alkali metals are in Group 1 (1A) of the table. They have very similar properties. They are
highly reactive, and are never found as free metals in their natural state. In other words, they are always
found combined with other elements in the form of compounds. When the elements in this group
combine with chlorine they always combine in a ratio of 1:1 to form a new compound. Color the alkali
metals green on your periodic table. Do not include hydrogen!
The alkaline earth metals are in Group 2 (2A) of the table. They also have similar properties. The
elements in this group combine with chlorine in a ratio of 1:2 to form a new compound. Color the alkali
earth metals blue.
The halogens are in group 17 (7A) of the table. The elements in this group combine with
hydrogen in a ratio of 1:1 to form a new compound. Color the halogens yellow.
The noble gases are in group 18 (8A) of the table. They are all gases and are extremely
unreactive. They do not combine with other elements to form new compounds under normal conditions.
They have also been called the inert gases. Some periodic tables classify the noble gases as nonmetals
while others simply refer to the noble gases as a group unto themselves. Color the noble gases red.
The eight rows going across the table are called periods. For easy reference the periods are
numbered one through seven going down the left hand side of the table. The word periodicity refers to
the reoccurring patterns, which repeat over and over again in the table. As you get to know the periodic
table these various patterns will become clearer.
The lanthanides and the actinides are organized in rows, not columns. They are found in the 6th
and
periods (not the 8th and 9th). They are normally shown below the periodic table mainly for
convenience. The lanthanides are also called the rare earth elements, although they are not considered
particularly rare anymore except for promethium, Pm, which is created artificially. The element
lanthanum, La, is included in the lanthanides by most periodic tables and accounts for the name of this
set of elements. Similarly, the element Ac, actinium, is included in the actinides, and gives this set of
elements their name. The actinide series of the elements are all radioactive. Only the first four have been
found in nature. The rest have been created synthetically. The synthetic actinides are often referred to as
the transuranium elements. Color the lanthanides and actinides brown. The rest of your periodic table
should cover the middle section – these are the transition metals and post-transition metals, all of
which are metals. Leave these elements white.
7th
Answer these questions in your notebook. Use complete sentences.
1. The elements copper and gold are both relatively unreactive. It is easy to bend and shape both
metals. Both are used to make coins and jewelry. Does the similarity in their properties make
sense? Explain why or why not. Can you name an element besides copper that would have
properties similar to gold?
2. Lithium, an alkali metal, and chlorine, a halogen, combine to form lithium chloride. Write the
correct formula for lithium chloride.
3. Calcium, an alkaline earth metal, and iodine, a halogen, combine to form calcium iodide. Write the
correct formula for calcium iodide.
4. Identify the correct chemical group (or category) for each element listed below:
a. Europium
d. Iodine
g. Barium
b. Uranium
e. Xenon
h. Rubidium
c. Antimony
f. Molybdenum
5. What element has average atomic mass 137.3? Do you think the element would be relatively
reactive or nonreactive?
6. The 6 groups labeled 3B-2B are called the transition metals. Are the transition metals solids,
liquids or gases at room temperature?
7. Find strontium, Sr, on the periodic table
a. Find the atomic number, average atomic mass, period and group for Sr.
b. Would you expect Sr to be a solid, liquid or gas at room temperature?
c. Is Sr a metal, metalloid or nonmetal? How can you tell?
d. Do you expect Sr to be reactive or not? Why?
8. Find selenium, Se, on the periodic table
a. Find the atomic number, average atomic mass, period and group for Se
b. Would you expect Se to be a solid, liquid or gas at room temperature?
c. Is Se a metal, metalloid or nonmetal? How can you tell?
d. Do you expect Se to be reactive or not? Why?
9. Describe how reactivity changes as you go DOWN group 1A.
10. In period 4, how does reactivity change as you move across a period?
11. Name two elements that have properties similar to those of Be AND have average atomic masses
higher than 130.
12. Which of these elements are solids at room temperature?
F, Ti, Pb, O, K, Si
13. Which of these elements are nonmetals?
Br, C, B, Tl, P, Al
14. Which TWO of these elements are the least reactive? Explain your thinking.
Cl, Ba, Cu, Rb, K, Hg
15. Do you think you can you make jewelry out of the elements listed below? Explain your thinking.
Br, Na, Pt, Pd