Download 7-1 Notes: Arranging the Elements

7-1 Notes: Arranging the Elements
Dmitri Menedeleev, who was a Russian chemist, discovered a pattern to the
elements in 1869. He saw that when the elements were arranged in order of
increasing atomic mass, those that had similar properties fell into a repeating
pattern. The pattern was periodic, meaning “happening at regular intervals.”
His table became known as the periodic table of the elements.
A few elements’ properties did not fit the pattern in Mendeleev’s table. All
elements fit the pattern in Mendeleev’s periodic table when they were
arranged by atomic number. In the modern periodic table, elements are
arranged horizontally in order of increasing atomic number. Elements that
have similar chemical properties are grouped in vertical columns.
Elements are classified according to their properties as metals, nonmetals, and
metalloids. The number of electrons in the outer energy level of an atom helps
determine the category in which an element belongs. The zigzag line on the
periodic table can help you recognize metals, nonmetals, and metalloids.
Most elements are metals. Metals are found to the left of the zigzag line.
Atoms of most metals have few electrons in their outer energy level.
Nonmetals are found to the right of the zigzag line. Atoms of most nonmetals
have an almost complete set of electrons in their outer energy level. More than
half of the nonmetals are gases at room temperature. Metalloids, also called
semimetals or semiconductors, are the elements that border the zigzag line.
Atoms of metalloids have about half a complete set of electrons in their outer
energy level.
Each square on the periodic table includes an element’s name, chemical
symbol, atomic number, and atomic mass. Each horizontal row of elements
(from left to right) on the periodic table is called a period. Each vertical
column of elements (from top to bottom) is called a group. Because elements
in the same group have similar properties, a group is also called a family.
All elements follow the periodic law. The periodic law states that the
repeating chemical and physical properties of elements change with the
elements’ atomic numbers.
Unit 3 (Ch. 7) – The Atom/Periodic Table
Bach
10/27/09
Section 7-1 Review
1. In the modern periodic table, how are elements arranged
horizontally?
Horizontally, elements are arranged according to increasing atomic
number.
2. How are elements arranged vertically in the modern periodic
table?
Vertically, elements are arranged according to similar chemical
properties.
3. Where are metals located on the periodic table?
Metals are found to the left of the zigzag line on the periodic table.
4. Where are nonmetals found on the periodic table?
Nonmetals are found to the right of the zigzag line on the periodic
table.
5. Where are metalloids found on the periodic table?
Metalloids are found on the border of the zigzag line on the periodic
table.
6. Name 3 properties of metals and 3 properties of nonmetals.
Metals = Most are shiny, solid at room temperature, malleable,
ductile, good conductors of heat and electricity.
Nonmetals = Most are dull, gases at room temperature, brittle, not
good conductors of heat or electricity.
7. What is the difference between a period and a group?
Period = Horizontal rows of elements in the periodic table.
Group = A vertical column of elements in the periodic table that
usually share similar chemical and physical properties.
8. What is the periodic law?
The law that states that the repeating chemical and physical
properties of elements change periodically with the atomic numbers
of the elements.
Unit 3 (Ch. 7) – The Atom/Periodic Table
Bach
10/27/09
7-1 Notes: Arranging the Elements
Dmitri _______________, who was a Russian chemist, discovered a pattern to
the elements in 1869. He saw that when the elements were arranged in order of
increasing atomic _______, those that had similar properties fell into a
repeating pattern. The pattern was ___________, meaning “happening at
regular intervals.” His table became known as the __________ ________ of
the elements.
A few elements’ ____________ did not fit the pattern in Mendeleev’s table.
All elements fit the pattern in Mendeleev’s periodic table when they were
arranged by atomic ___________. In the modern periodic table, elements are
arranged _______________ in order of increasing atomic number. Elements
that have similar chemical properties are grouped in ___________ columns.
Elements are classified according to their ____________ as metals, nonmetals,
and metalloids. The number of ____________ in the outer energy level of an
atom helps determine the category in which an element belongs. The
__________ line on the periodic table can help you recognize metals,
nonmetals, and metalloids.
Most elements are __________. Metals are found to the _______ of the zigzag
line. Atoms of most metals have ______ electrons in their outer energy level.
Nonmetals are found to the _________ of the zigzag line. Atoms of most
nonmetals have an almost _____________ set of electrons in their outer
energy level. More than half of the nonmetals are _________ at room
temperature. Metalloids, also called _______________ or semiconductors, are
the elements that border the zigzag line. Atoms of metalloids have about
________ a complete set of electrons in their outer energy level.
Each square on the periodic table includes an element’s ________, chemical
symbol, atomic number, and atomic _______. Each horizontal row of
elements (from left to right) on the periodic table is called a __________. Each
vertical column of elements (from top to bottom) is called a ________.
Because elements in the same group have similar properties, a group is also
called a ___________.
All elements follow the __________ ______. The periodic law states that the
repeating chemical and physical properties of elements change with the
elements’ __________ ___________.
Unit 3 (Ch. 7) – The Atom/Periodic Table
Bach
10/27/09
Section 7-1 Review
1. In the modern periodic table, how are elements arranged
horizontally?
2. How are elements arranged vertically in the modern periodic
table?
3. Where are metals located on the periodic table?
4. Where are nonmetals found on the periodic table?
5. Where are metalloids found on the periodic table?
6. Name 3 properties of metals and 3 properties of nonmetals.
7. What is the difference between a period and a group?
8. What is the periodic law?
Unit 3 (Ch. 7) – The Atom/Periodic Table
Bach
10/27/09