Elements and the Periodic Table Introduction to Atoms Organizing the Elements Metals Nonmetals and...
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Transcript of Elements and the Periodic Table Introduction to Atoms Organizing the Elements Metals Nonmetals and...
Elements and the Periodic Table
Introduction to Atoms
Organizing the Elements
Metals
Nonmetals and Metalloids
Elements From Stardust
Table of Contents
Elements and the Periodic Table
Structure of an Atom
A carbon atom consists of protons and neutrons in a nucleus that is surrounded by electrons.
- Introduction to Atoms
Elements and the Periodic Table
Models of Atoms
- Introduction to Atoms
For over two centuries, scientists have created models of atoms in an effort to understand why matter behaves as it does. As scientists have learned more, the model of the atom has changed.
Elements and the Periodic Table
4
Rutherford’s experiment circa 1909(alpha scattering experiment)
1/8000 alpha particle were deflected
Like a Toyota hitting a Mack truck!!Rutherford had discovered the
nucleus
Elements and the Periodic Table
5
Alpha particles scattered from the gold foil
Elements and the Periodic Table
6
Properties of Subatomic Particles
Elements and the Periodic Table
Isotopes
Atoms of all isotopes of carbon contain six protons, but they differ in the number of neutrons. Carbon-12 is the most common isotope.
- Introduction to Atoms
Elements and the Periodic Table
Structure of an Atom
Q. What particles are in the center of the atom?
A. Protons and neutrons
Q. What particles move around the outside of the nucleus?
A. Electrons
- Introduction to Atoms
Elements and the Periodic Table
End of Section:Introduction to
Atoms
Elements and the Periodic Table
10
Periodic Table DevelopmentSeveral Early Schemes to Organize Elements
Mendeleev & Meyer (1869)
Organized elements by atomic mass
Noticed a pattern of properties when he arranged elements in order of increasing atomic
mass
Moseley (1913)
Post-doctoral student working in Rutherford’s lab
Organized elements by atomic number at age 26
Tragically killed in WW I
Elements and the Periodic Table
Elements and the Periodic Table
Organization of the Periodic Table
The 18 columns of the periodic table reflect a repeating pattern of properties that generally occur across a period.
- Organizing the Elements
Elements and the Periodic Table
13
Complete Periodic Table
Elements and the Periodic Table
Finding Data on Elements
Each square of the periodic table includes an element’s atomic number, chemical symbol, name, and atomic mass.
- Organizing the Elements
Elements and the Periodic Table
15
Fusion
Elements and the Periodic Table
Formation of the elements• Fusion of Hydrogen isotopes in stars releases energy• Heavier elements are forms due to fusion and the and very large gravitational
forces in the center of stars•Heavier elements like carbon, nitrogen, oxygen are produced in large stars
• Elements heavier than oxygen are produced in supernova at temperatures of a billion degrees!
Elements and the Periodic Table
What pattern of elements did Mendeleev discover?
Patterns appeared when the elements were arranged in order of increasing atomic mass.
What data about elements is found in the periodic table?
Atomic number, chemical symbols and names, and average atomic mass
How are elements organized in the periodic table?
Elements are organized in periods and groups based on their properties.
Question Answers
- Organizing the Elements
Elements and the Periodic Table
End of Section:Organizing the
Elements
Elements and the Periodic Table
Metals in the Periodic Table
The metals in Group 1, from lithium to francium, are called the alkali metals. Alkali metals react with atoms of other elements by losing one electron.
- Metals
Elements and the Periodic Table
Metals in the Periodic Table
Group 2 of the periodic table contains the alkaline earth metals. These elements are not as reactive as the metals in Group 1, but they are more reactive than most other metals.
- Metals
Elements and the Periodic Table
Melting Points in a Group of Elements
The properties of elements within a single group in the periodic table often vary in a certain pattern. The following graph shows the melting points of Group 1 elements (alkali metals) from lithium to francium.
- Metals
Elements and the Periodic Table
Melting Points in a Group of Elements
Melting points decrease from lithium to francium.
Reading Graphs:
As you look at Group 1 from lithium to francium, describe how the melting points of the alkali metals change.
- Metals
Elements and the Periodic Table
Melting Points in a Group of Elements
New element 119 should have a melting point of approximately 25ºC.
Predicting:
If element number 119 were synthesized, it would fall below francium in Group 1 of the periodic table. Predict the approximate melting point of new element 119.
- Metals
Elements and the Periodic Table
Melting Points in a Group of Elements
None of the alkali metals are liquids at room temperature. Cesium and francium might melt if you could hold them in your hand.
Interpreting Data:
Room temperature is usually about 22ºC. Human body temperature is 27ºC. Which of the alkali metals are liquids at room temperature? Which might melt if you could hold them in your hand?
- Metals
Elements and the Periodic Table
Metals in the Periodic Table
The transition metals are less reactive than the metals in Groups 1 and 2.
- Metals
Elements and the Periodic Table
Metals in the Periodic Table
Only some of the elements in Groups 13 through 15 of the periodic table are metals. These metals are not nearly as reactive as those on the left side of the table.
- Metals
Elements and the Periodic Table
Metals in the Periodic Table
Lanthanides are soft, malleable, shiny metals with high conductivity.
- Metals
Elements and the Periodic Table
Metals in the Periodic Table
The elements below the lanthanides are called actinides. Many of these elements are so unstable that they last for only a fraction of a second after they are made.
- Metals
Elements and the Periodic Table
What You Know
What You Learned
Using Prior KnowledgeBefore you read, write what you know about metals in a graphic organizer like the one below. As you read, write what you learn.
1. Metals are shiny.2. Some metals are magnetic.
1. Ductile metals can be pulled into a wire.2. Alkali metals react by losing one electron.
- Metals
Elements and the Periodic Table
End of Section:Metals
Elements and the Periodic Table
Properties of Nonmetals
When nonmetals react with metals, one or more electrons move from the metal atoms to the nonmetal atoms.
- Nonmetals and Metalloids
Elements and the Periodic Table
Families of Nonmetals
Each element in the carbon family has atoms that can gain, lose, or share four electrons when reacting with atoms of other elements.
- Nonmetals and Metalloids
Elements and the Periodic Table
Families of Nonmetals
Group 15, the nitrogen family, contains two nonmetals: nitrogen and phosphorus. These non-metals usually gain or share three electrons when reacting with atoms of other elements.
- Nonmetals and Metalloids
Elements and the Periodic Table
Families of Nonmetals
Group 16, the oxygen family, contains three nonmetals: oxygen, sulfur, and selenium. These elements usually gain or share two electrons when reacting with atoms of other elements.
- Nonmetals and Metalloids
Elements and the Periodic Table
Families of Nonmetals
The Group 17 elements are the most reactive nonmetals. Atoms of these elements easily form compounds by sharing or gaining one electron when reacting with atoms of other elements.
- Nonmetals and Metalloids
Elements and the Periodic Table
Families of Nonmetals
The elements in Group 18 are known as the noble gases. They do not ordinarily form compounds because atoms of noble gases do not usually gain, lose, or share electrons.
- Nonmetals and Metalloids
Elements and the Periodic Table
Families of Nonmetals
Because the chemical properties of hydrogen differ very much from those of the other elements, it really cannot be grouped into a family.
- Nonmetals and Metalloids
Elements and the Periodic Table
The Metalloids
The metalloids have some characteristics of both metals and nonmetals. The most useful property of the metalloids is their varying ability to conduct electricity.
- Nonmetals and Metalloids
Elements and the Periodic Table
Using Prior KnowledgeBefore you read, write what you know about nonmetals in a graphic organizer like the one below. As you read, write what you learn.
What You Know
What You Learned
1. Nonmetals are not shiny.2. Nonmetals are not magnetic.
1. Nonmetals are dull and brittle.2. Metalloids have characteristics of metals and
nonmetals.
- Nonmetals and Metalloids
Elements and the Periodic Table
End of Section:Nonmetals and
Metalloids
Elements and the Periodic Table
How Elements Form in Stars
Nuclear fusion, which occurs in stars on a huge scale, combines smaller nuclei into larger nuclei, creating heavier elements.
- Elements From Stardust
Elements and the Periodic Table
SequencingAs you read, make a flowchart like the one below that shows how elements are formed in stars. Write the steps in separate boxes in the flowchart in the order in which they occur. Hydrogen nuclei fuse, forming helium.
Helium nuclei fuse, forming beryllium.
Fusion continues in smaller stars, forming elements up to oxygen.
Fusion in larger stars produces heavier elements up to iron.
The heaviest elements form during supernova explosions of the most massive stars.
- Elements From Stardust
Elements and the Periodic Table
Links on Nuclear Fusion
Click the SciLinks button for links on nuclear fusion.
- Elements From Stardust
Elements and the Periodic Table
End of Section:Elements From
Stardust
Elements and the Periodic Table
Graphic Organizer
Elements
Atomicnumber
Periods Families
Groups
Periodic table
Rows Columns
Patterns of properties
organizes
called called
or
is made up of
and shows
in order of increasing
Elements and the Periodic Table
End of Section:Graphic Organizer