GENERAL PROPERTIES OF GROUPS IN PERIODIC TABLE
Group I - Alkali metals:
·
The most reactive metals
on the PT.
·
They are all soft,
silvery solids with low melting and boiling points.
·
Very good conductors of
electricity and heat. Examples:
Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Caesium (Cs), Francium
(Fr)
Group II - Alkaline
earth metals:
·
Are less reactive than
the alkali metals, but they are still very reactive metals.
·
They are all hard,
silvery solids with high melting and boiling points.
·
They are also good
conductors of electricity and heat. Examples: Beryllium (Be), Magnesium (Mg),
Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra)
Group VII - Halogens:
·
The halogens are very
reactive non-metals.
·
They are all gases
(except iodine, which is a solid) with a pungent odor.
·
They are also very
corrosive and can react with many different substances. Examples: Fluorine (F),
Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At)
Group VIII (0) - Noble
gases:
·
The noble gases are the
least reactive elements on the periodic table.
·
They are all colorless,
odorless, and monatomic gases.
·
They are also very
stable and do not react with many other substances. Examples: Helium (He), Neon
(Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn)
Other
important groups include:
·
Transition
metals: The transition metals are located in the middle of
the periodic table. They are all hard, shiny metals with high melting
and boiling points. They are also good conductors of electricity and
heat. Many transition metals have variable valencies and can form colored
compounds.
·
Metals: Most
of the elements in the periodic table are metals. Metals are generally
hard, shiny solids with high melting and boiling points. They are
also good conductors of electricity and heat.
·
Nonmetals: Nonmetals
are located on the right side of the periodic table. They are generally
gases or solids with low melting and boiling points. They are also poor
conductors of electricity and heat.
Trends in groups
There
are a number of trends in groups on the periodic table. These trends include:
·
Reactivity: The
reactivity of metals increases down the group and the reactivity of non-metals
decreases down the group.
·
Atomic
radius: The atomic radius of elements increases down the
group.
·
Melting
and boiling points: The melting and boiling points
of elements generally increase down the group.
·
Electron
affinity: The electron affinity of elements generally increases
down the group.
·
Ionization
energy: The ionization energy of elements generally
decreases down the group.
QUIZ
i.
Name
the group of elements that are all soft, silvery-white metals and react readily
with oxygen and water.
ii.
Explain
why the elements in Group VII are very reactive.
iii.
What
is the general trend in reactivity down Group I?
iv.
Predict
the properties of the element with atomic number 119, based on its position on
the periodic table
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