Topic 1 - Matter and Energy - Revsworld

Topic 2 - The Periodic Table
18. Groups and Group properties: Relating properties to Group
Concept Task: Be able to relate element’s name to a given property.
Study each example question below, and note the explanations for each correct choice.
Example 6:
Which element exist as a diatomic molecule?
1) Mg 2) Fe 3) Br 4) He
Answer: Choice 3. Br is a halogen. Halogens exist as diatomic molecules
.
Example 7:
Which element is likely to gain electron during bonding?
1) S 2) Cr 3) Ne 4) Na
Answer: Choice 1. S (sulfur) is a nonmetal. Nonmetals are likely to gain electrons.
Example 8:
An unknown element Z bonds with oxygen to produce an oxide with a general formula of ZO. Element Z
is likely
1) Potassium 2) Beryllium 3) Aluminum 4) Ar
Answer: Choice 2: Oxygen combines with Group 2 alkaline earth in a 1:1 ratio (ZO). (See summary Table)
Beryllium (Be) is a Group 2 alkaline earth metal. (See Periodic Table)
Example 9:
Which is likely a colorful compound?
1) KCl 2)MnCl 2 3) AlCl 3 4) SrCl 2
Answer: Choice 2. Transition metals form colorful compounds. Mn (in MnCl 2 ) is a transition metal.
Introduction
Lesson 3. Periodic Trends
Periodic trends refer to patterns of properties that exist as elements are considered from one end of
the table to the other.
Trend in atomic number is a good example (and the most obvious) of a periodic trend found on the
Periodic Table.
It is easy to see that as elements are considered one after the other from:
Left to Right across a Period: Atomic number of the elements increases
Bottom to Top up a Group: Atomic number of the elements decreases
Many other trends exist on the periodic table even though they are not so obvious.
In this lesson, you will learn of the following trends.
Trends in atomic and ionic radius (size).
Trends in metallic and nonmetallic properties.
Trends in electronegativity and ionization energy.
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