unit 1 lesson 13 ppt
TRANSCRIPT
Do Now
Explain in detail how you arrange your
clothes at home.
How are products arranged and stacked on shelves
in a grocery store?
How is the periodic table used to classify and provide information about all known elements?
• How are elements arranged on the periodic table?
• What can you learn about elements from the periodic table?
Using the Periodic Table
How does sorting help scientists understand
What they are studying?
Sorting helps scientists understand how things
are similar and how they are different
Explain in your own words what you think the
periodic table is?
• The periodic table is a chart of the elements arranged into rows and columns according to their physical and chemical properties.
• It can be used to determine the relationships among the elements.
What is the periodic table?
100 table The periodic table is a chart of the elements arranged into rows and columns according to their physical and chemical properties.
• In 1869 Dimitri Mendeleev was working on a way to classify elements.
• At the time, more than 60 elements had been discovered.
Developing a Periodic Table
Russian chemist and
Teacher who lived in
the 1800s
Developing a Periodic Table
Periodic table of the
elements; a system for
organizing the elements
• Mendeleev studied the physical properties such as density, color, melting point and atomic mass of each element.
• He also noted chemical properties such as how each element reacted with other elements.
• Mendeleev arranged the elements in a list using their atomic mass.
Developing a Periodic Table
Mendeleev noticed in his table that melting point is one property that shows a repeating pattern.
• Mendeleev’s periodic table enabled scientists to relate the properties of the known elements to their position on the table
• However, the table had a problem!! Some elements seemed out of place.
Problems with Mendeleev’s Table
• In the early 1900’s, the scientist Henry Moseley solved the problem with the periodic table.
• Moseley listed the elements according to increasing ATOMIC NUMBER
Henry Moseley
When Moseley listed the elements according to atomic number, columns contained elements with similar properties, such as copper, silver, and gold.
Developing a Periodic Table (cont.)
What determines where an element is located on the periodic table you use today?
You can identify many of the properties of an element from its placement on the periodic table.
Today’s Periodic Table
period
Science Use the completion of a cycle; a row on the periodic table
Common Use a point used to mark the end of a sentence; a time frame
The table is organized into columns, rows, and blocks, which are based on certain patterns of properties.
Today’s Periodic Table (cont.)
• The element key shows an element’s chemical symbol, atomic number, and atomic mass.
• The key also contains a symbol that shows the state of matter at room temperature.
• A group is a column on the periodic table.
• Elements in the same group have similar chemical properties and react with other elements in similar ways.
Today’s Periodic Table (cont.)
Today’s Periodic Table (cont.)
What can you infer about the properties of two elements in the same group?
• The rows on the periodic table are called periods.
• The atomic number of each element increases by one as you read from left to right across each period.
Today’s Periodic Table (cont.)
• Metals are on the left side and in the middle of the periodic table.
• With the exception of hydrogen, nonmetals are located on the right side of the periodic table.
• Between the metals and the nonmetals on the periodic table are the metalloids.
Today’s Periodic Table (cont.)
Even today, new elements are created in laboratories, named, and added to the present-day periodic table.
How Scientists Use the Periodic Table
• Scientists can use the periodic table to predict the properties of new elements they create.
• The periodic table contains more than 100 elements, each with its unique properties that differ from the properties of other elements.
How Scientists Use the Periodic Table (cont.)
• On the periodic table, elements are arranged according to increasing atomic numbers and similar properties.
• A column of the periodic table is called a group. Elements in the same group have similar properties.
• A row of the periodic table is called a period. Properties of elements repeat in the same pattern from left to right across each period.
A. columns of increasing atomic mass
B. rows of increasing atomic mass
C. rows of increasing atomic number
D. rows of decreasing atomic number
How did Mendeleev arrange elements when he first used a table to classify elements?
A. chemical symbol
B. atomic number
C. atomic mass
D. all of these
What does the element key of a periodic table indicate?
A. top half
B. right side
C. left side
D. bottom half
Where are all nonmetals (with the exception of hydrogen) located on the periodic table?
1. The elements on the periodic table are arranged in rows in the order they were discovered.
2. The properties of an element are related to the element’s location on the periodic table.
Do you agree or disagree?
• What elements are metals?
• What are the properties of metals?
Metals
• metal
• luster
• ductility
• malleability
Metals
• alkali metal
• alkaline earth metal
• transition element
• More than three-quarters of the elements on the periodic table are metals.
• With the exception of hydrogen, all of the elements in groups 1-12 on the periodic table are metals.
• Some of the elements in groups 13-15 are metals.
What is a metal?
To be a metal, an element must have certain properties.
What is a metal? (cont.)
How does the position of an element on the periodic table allow you to determine if the element is a metal?
• A metal is an element that is generally shiny. It is easily pulled into wires or hammered into thin sheets. A metal is a good conductor of electricity and thermal energy.
• Luster describes the ability of a metal to reflect light.
What is a metal? (cont.)
Ductility is the ability to be pulled into thin wires.
What is a metal? (cont.)
ductility
from Latin ductilis, means “may be led or drawn”
• Malleability is the ability of a substance to be hammered or rolled into sheets.
• Gold is so malleable that it can be hammered into thin sheets.
• In general the density, strength, boiling point, and melting point of a metal are greater than those of other elements.
What is a metal? (cont.)
What is a metal? (cont.)
What are some physical properties of metals?
• The elements in group 1 are called alkali metals.
• The alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium.
• Alkali metals react quickly with other elements, such as oxygen and in nature, occur only in compounds.
Group 1: Alkali Metals
Alkali metals react violently with water. They are also soft enough to be cut with a knife.
Group 1: Alkali Metals (cont.)
• The elements in group 2 on the periodic table are called alkaline earth metals.
• The alkaline earth metals are beryllium, magnesium, calcium, strontium, barium, and radium.
Group 2: Alkaline Earth Metals
Pure alkaline earth metals do not occur naturally but instead combine with other elements and form compounds.
Group 2: Alkaline Earth Metals (cont.)
Groups 3-12: Transition ElementsThe elements in groups 3-12 are called transition elements.
Groups 3-12: Transition Elements (cont.)
• Transition elements are in a block at the center and two rows at the bottom of the periodic table.
• Many colorful materials contain small amounts of transition elements.
• All transition elements are metals with higher melting points, greater strength, and higher densities than the alkali metals and the alkaline earth metals.
• Because of their high densities, strength, and resistance to corrosion, transition elements make good building materials.
Groups 3-12: Transition Elements (cont.)
Groups 3-12: Transition Elements (cont.)
Two rows of transition elements—the lanthanide and actinide series—were removed from the main part of the table so that periods 6 and 7 were not longer than the other periods.
Metallic properties include luster, malleability, and electrical conductivity.
Patterns in Properties of Metals
• Properties of metals include conductivity, luster, malleability, and ductility.
• Alkali metals and alkaline earth metals react easily with other elements. These metals make up groups 1 and 2 on the periodic table.
• Transition elements make up groups 3-12 and the lanthanide and actinide series on the periodic table.
A. malleability
B. ductility
C. luster
D. alkaline
Which term describes the ability of a metal to reflect light?
A. They all belong to the same period.
B. They react quickly with other elements.
C. They include gold.
D. All of the above are true.
Which of the following is true of alkaline earth metals?
A. Transition elements have higher melting points.
B. Transition elements have greater strength.
C. Transition elements have higher densities.
D. All of the above are true.
Which of the following distinguishes transition elements from alkali metals?
3. Fewer than half of the elements are metals.
4. Metals are usually good conductors of electricity.
Do you agree or disagree?
• Where are nonmetals and metalloids on the periodic table?
• What are the properties of nonmetals and metalloids?
Nonmetals and Metalloids
• nonmetal
• halogen
• noble gas
• metalloid
• semiconductor
Nonmetals and Metalloids
More than 96 percent of the mass of the human body comes from four nonmetals–oxygen, carbon, hydrogen, and nitrogen.
The Elements of Life
• Nonmetals are elements that have no metallic properties.
• The four elements that make up most of the human body, along with phosphorus and sulfur, are the six elements in proteins, fats, nucleic acids, and other large molecules in your body and in all other living things.
The Elements of Life (cont.)
• Nonmetals have properties that are different from those of metals.
• Many nonmetals are gases at room temperature and those that are solid at room temperature have a dull surface, which means they have no luster.
• Because nonmetals are poor conductors of electricity and thermal energy, they are good insulators.
How are nonmetals different from metals?
Phosphorus and carbon are dull, brittle solids that do not conduct thermal energy or electricity.
How are nonmetals different from metals? (cont.)
What properties do nonmetals have?
An element in group 17 of the periodic table is galled a halogen.
How are nonmetals different from metals? (cont.)
halogen
from Greek hals, means “salt”; and –gen, means “to produce”
The term halogen refers to an element that can react with a metal and form a salt.
How are nonmetals different from metals? (cont.)
• Halogens react readily with other elements and form compounds.
• Halogens can only occur naturally in compounds.
• In general, halogens are less reactive as you move down the group.
How are nonmetals different from metals? (cont.)
The elements in group 18 are known as the noble gases.
How are nonmetals different from metals? (cont.)
• Unlike the halogens, the only way elements in this group react with other elements is under special conditions in a laboratory.
• Of all the elements, hydrogen has the smallest atomic mass and is the most common element in the universe.
How are nonmetals different from metals? (cont.)
• Hydrogen is most often classified as a nonmetal because it has many properties like those of nonmetals.
• However, hydrogen also has some properties similar to those of the group 1 alkali metals.
• Under conditions on Earth, hydrogen usually behaves as a nonmetal.
How are nonmetals different from metals? (cont.)
Between the metals and the nonmetals on the periodic table are elements known as metalloids.
• A metalloid is an element that has physical and chemical properties of both metals and nonmetals.
• The elements boron, silicon, germanium, arsenic, antimony, tellurium, polonium, and astatine are metalloids.
• Silicon is the most abundant metalloid in the universe.
Metalloids (cont.)
• A property of metalloids is the ability to act as a semiconductor.
• A semiconductor conducts electricity at high temperatures, but not at low temperatures.
Metalloids (cont.)
Silicon is used in making semiconductor devices for computers and other electronic products.
Metalloids (cont.)
semiconductor
from Latin semi-, means “half”; and conducere, means “to bring together”
• An element’s position on the periodic table tells you a lot about the element.
• Understanding the properties of elements can help you decide which element to use in a given situation.
Metals, Nonmetals, and Metalloids
• A nonmetal is an element that has no metallic properties. Solid nonmetals are dull and brittle and do not conduct thermal energy or electricity.
• Halogens and noble gases are nonmetals. These elements are found in group 17 and group 18 of the periodic table.
• Metalloids have some metallic properties and some nonmetallic properties. The most important use of metalloids is as semiconductors.
A. halogen
B. nonmetals
C. noble gases
D. metalloid
What term refers to elements in group 18 that only react with other elements under special laboratory conditions?
A. metal
B. conductor
C. halogen
D. semiconductor
Which term refers to an element that conducts electricity at high temperatures, but not at low temperatures?
A. halogen
B. noble gas
C. semiconductor
D. none of the above
Which term refers to an element that can react with a metal and form a salt?
5. Most of the elements in living things are nonmetals.
6. Even though they look very different, oxygen and sulfur share some similar properties.
Do you agree or disagree?
Key Concept Summary
Interactive Concept Map
Chapter Review
Standardized Test Practice
Elements are grouped and organized on the periodic table according to increasing atomic number and similar properties.
• Elements are organized on the periodic table by increasing atomic number and similar properties.
• Elements in the same group, or column, of the periodic table have similar properties.
• Elements’ properties change across a period, which is a row of the periodic table.
• Each element key on the periodic table provides the name, symbol, atomic number, and atomic mass for an element.
Lesson 1: Using the Periodic Table
Lesson 2: Metals
• Metals are located on the left and middle parts of the periodic table.
• Metals are elements that have ductility, malleability, luster, and conductivity.
• The alkali metals are in group 1 of the periodic table, and the alkaline earth metals are in group 2.
• Transition elements are metals in groups 3-12 of the periodic table, as well as the lanthanide and actinide series.
Lesson 3: Nonmetals and Metalloids
• Nonmetals are on the right side of the periodic table, and metalloids are located between metals and nonmetals.
• Nonmetals are elements that have no metallic properties. Solid nonmetals are dull in appearance, brittle, and do not conduct electricity. Metalloids are elements that have properties of both metals and nonmetals.
• Some metalloids are semiconductors.
• Elements in group 17 are called halogens, and elements in group 18 are noble gases.
A. no
B. yes
C. Maybe, but it has never been done.
D. none of these
Can new elements created in laboratories be added to the periodic table?
A. group
B. row
C. period
D. block
What is another name for a column on the periodic table?
A. luster
B. ductility
C. malleability
D. alkali
Which term refers to a metal’s ability to be pulled into thin wires?
A. metalloids
B. metals
C. nonmetals
D. semiconductors
What term refers to elements that have no metallic properties?
A. boron
B. silicon
C. nitrogen
D. none of these
More than 96 percent of the mass of the human body comes from four nonmetals—oxygen, carbon, hydrogen, and what else?
A. top
B. left side and in the middle
C. right side
D. bottom
Where are metals found on the periodic table?
A. alkali metals
B. alkaline earth metals
C. transitional elements
D. nonmetals
Which group of metals includes sodium, potassium, and cesium?
A. luster
B. ductility
C. malleability
D. conductivity
Which term refers to the ability of a substance to be hammered or rolled into sheets?
A. carbon
B. sulfur
C. hydrogen
D. nitrogen
Of all the elements, which one has the smallest atomic mass?
A. increase
B. decrease
C. remain the same
D. none of these
Metallic properties of the elements tend to do what as you move down a group?