3.) determine the number of protons, neutrons, and electrons, and the mass of an element using the...
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The Periodic Table
Alabama Course of Study Standard
3.) Determine the number of protons, neutrons, and electrons, and the mass of an element using the periodic table.
• Locating metals, nonmetals, metalloids, and noble gases on the periodic table
• Using data about the number of electrons in the outer shell of an atom to determine its reactivity
Bell Ringer Give the elemental symbol for the elements below:
1 Hydrogen2 Sulfur3 Flourine4 Helium5 Silicon6 Boron7 Carbon8 Nitrogen9 Sodium10 Calcium
Bell Ringer Give the elemental symbol for the elements below:
1 Hydrogen H2 Sulfur S3 Fluorine F4 Helium He5 SiliconSi6 Boron B7 Carbon C8 Nitrogen N9 Sodium Na10 Calcium Ca
You are going to create a seating chart for the
students in this class. The purpose is to organize the class in rows or groups. You can group them any way that you want, but
you must have a reason for placing each student where you place them.
Write the name of each of your classmates in the place that you think they should sit.
Now, explain why/how you grouped the students the way that you did.
Start-Up Activity
Suppose that you
went to a movie store and all the dvd’s were mixed together. How could you tell the comedies from the action movies? If the dvd’s were not arranged in a pattern, you wouldn’t know what kind of movie you had chosen!
Arranging the Elements
I need 3 volunteers! Two stand that the front next to each other. Let’s list characteristics that they share. Swap one student out for the third. Let’s list characteristics that they share. Now, let’s compare the two lists. What are the similarities and differences?
Demonstration
Scientists in the early 1860s had a problem. At that time, scientists knew of some of the *properties of more
than 60 elements. No one had organized the elements according to these properties. Organizing the elements according to their properties would help
scientists understand how elements interact with each other.
*property-An attribute, characteristic, or quality
1869….Dmitri Mendeleev
(Russian teacher and chemist) Discovered a pattern in the
elements Wrote the names and properties of
the elements on cards Arranged them in many different
ways (density, appearance, melting point, etc.)
After much thought, he arranged them in order of increasing atomic mass
Mendeleev’s Periodic Table
Mendeleev had arranged elements based on
increasing atomic mass.
How had Mendeleev arranged elements when he noticed a pattern?
Mendeleev saw that when the elements were arranged in
order of increasing atomic mass, those that had similar properties occurred in a repeating pattern.
This is the pattern that was periodic. Periodic means “happening at regular intervals”
Example: The days of the week are periodic. They repeat in the same
order every 7 days. Similarly, Mendeleev found that the elements’ properties
followed a pattern that repeated every 7 elements. His table became known as the periodic table of the
elements.
Periodic Properties of the Elements
He called this element eka-Aluminum.
Later it was renamed Gallium after its
discovery in 1875
Mendeleev’s first try at arranging the elements.
In approximately twenty words, explain what
we discussed today.
GIST
Who was credited with the
development of the periodic table?
Bell Ringer
The question marks show gaps in the pattern. Mendeleev predicted elements that had not been
found yet. He used the pattern he found to predict their
properties. By 1886, all of the gaps had been filled. His predictions were right.
Predicting Properties of Missing Elements
1914, Henry Moseley
British Scientist Determined the number
of protons –the atomic number-in an atom
Redesigned the periodic table to be arranged by atomic number
“Periodic” - Repeating patterns
Listed in order of increasing number of protons (atomic #)
Properties of elements repeat Periodic Law- when elements arranged by
increasing number of protons, properties repeat in pattern
The Modern Periodic Table
Turn to page 338-339 in your book. You are going to work in a small group to answer the following
questions.
1. What information does each square on the periodic table show?
2. How many elements are liquid at room temperature? 3. How many elements are gases at room temperature? 4. How many elements are metals? 5. How many elements are metalloids? 6. How many elements are nonmetals? 7. How many groups are the elements divided into? 8. How many periods are the elements divided into?
Co-op Learning Activity
Worksheet
What are periods in regards to the periodic
table?
Who came up with the modern version of the periodic table?
What did he do differently?
Exit Slip
What is the atomic number for Chlorine?
How many protons are in an atom of Na?
Bell Ringer
At first glance, you might think studying the periodic table
is like trying to explore a thick jungle without a guide– you can easily get lost! However, the table itself contains a lot of information that will help you along the way.
Elements are classified as metals, nonmetals, and metalloids, according to their properties.
The number of electrons in the outer energy level of an atom is one characteristic that helps determine which category an element belongs in.
The zigzag line on the periodic table can help you recognize which elements are metals, which are nonmetals, and which are metalloids.
The Periodic Table and Classes of Elements
Metals, Nonmetals, Metalloids
Foldable Create a 3 Panel Flip
Chart Fold your paper hot
dog style Make two cuts on one
side only Label the flaps Metal,
Nonmetal, and Metalloid
Most elements are metals.
They can be found to the left of the zigzag line on the table.
Atoms of most metals have few electrons in their outer energy level.
Most are solid at room temperature. Mercury is a liquid at
room temperature.
Metals
Metals are usually shiny (luster).
Mirrors have a thin coat of silver
Ductile-can be drawn into thin wires
Conductors- good for electricity and thermal energy
Malleable-can be flattened with a hammer and will not shatter
Properties of Metals
Found to the right of the zigzag line on the table
Atoms of most nonmetals have an almost complete set of electrons in their outer level.
Atoms of the elements in Group 18, the noble gases, have a complete set of electrons.
More than half of the nonmetals are gases at room temperature. (low boiling point)
Properties are generally opposite of metals
Non-Metals
Poor conductors of heat
and electricity Low boiling points Many are gases at room
temperature but can be found in solid or liquid form also
Not Malleable -Solid, non-metals are brittle (break easily)
Not Lustrous- not shiny Chemical properties vary
Non-Metals
Also called Semiconductors conduct electric current more
easily than nonmetals but less easily than metals
Border the zigzag line on the table
Have a bout half of a complete set of electrons in their outer energy level
Have properties similar to metals and non-metals
Metalloids
Tellurium is shiny, but it is
brittle and can be easily smashed into a powder.
Boron is almost as hard as a diamond, but it is also very brittle. At high temperatures, it is a good conductor of electrical current.
Metalloids
Decoding the Periodic Table
Element Key
Important information about an element is given in each square of the periodic table: its atomic number chemical symbol element name average atomic mass
6
CCarbon12.01
For example:Carbon has atomic # 6 (or has 6 protons), an average atomic mass of 12.01 and a symbol of C
One Pager
You have one page to summarize what we have learned today.
Be accurate.
Bell Ringer What is the atomic mass for Boron?
How many electrons are in an atom of Cl?
Physical and Chemical properties of elements in a row follow a repeating or periodic pattern as you move across the period.
Metallic properties decrease as we move to the right Ability to lose an electron decreases Ability to gain electrons increases
Variation Across a Period: Left to Right
-horizontal (left – right)-called a period-properties change greatly across
period-first element in period is very active
metal-last element in most periods is noble
gas-7 periods (number them on your
periodic table)
Rows in the Periodic Table
-vertical (top to bottom) -called groups or families-numbered 1-18 or 1A through 8A-elements in same family have
similar properties
Columns in the Periodic Table
Mendeleev developed the first periodic table
by listing the elements in order of increasing atomic mass.
He used his table to predict that elements with certain properties would be discovered later.
Summary
Properties of elements repeat in a regular, or
periodic, pattern.
Summary
Moseley rearranged the elements in order of
increasing atomic number.
Summary
The periodic law states that the repeating
chemical and physical properties of elements relate to and depend on elements’ atomic numbers.
Summary
Elements in the periodic table are classified as
metals, nonmetals, and metalloids.
Summary
Each element has a chemical symbol.
A horizontal row of elements is called a period.
Physical and chemical properties of elements change across each period.
Summary
A vertical column of elements is called a group
or family.
Elements in a group usually have similar properties.
Summary
Complete the worksheet.
Directed Reading B Worksheet
Bell Ringer
How do you know that a bird is a bird, that a kangaroo is a kangaroo, and that a shark is a shark? What characteristics of each animal help you to tell the animal apart?
Write what you know about how the groups on
the periodic table are organized.
Write what you would like to know more about.
K-W-L chart
You probably know a family with several
members who look a lot alike. The elements in a family or group in the periodic table often—but not always—have similar properties.
Grouping the Elements
outermost e-’s Responsible for chemical properties Elements in same group have same # of VE ALL atoms want full outer energy level (usually 8 VE) To get full outer energy level, some elements:
lose e- (metals) gain e- (non-metals) share electrons (some non-metals & metalloids)
What exactly are Valence electrons?
Atoms will often take, give, or share electrons with other atoms in order to have a complete set of electrons in their outer energy level. (We called these ions.)
Elements whose atoms undergo such processes are called reactive and can combine to form compounds.
Introducing the 18
major groups (families) on the modern Periodic
Table:
Alkali Metals (1)
-Group Contains: metals -1 valence electron (VE)-very reactive because they
like to give electron away soft, silver-white, shiny
metals Low density never found pure in nature When in their pure form,
they are stored in oil to keep them from reacting with water and oxygen in the air.- *Although the element
hydrogen appears above the alkali metals on the periodic table, it is not considered a member of Group 1.
reactivity increases
potassium
Label the Alkali Metals to your PT
Alkaline-Earth Metals (2)
-Group contains: metals -2 Valence Electrons Very reactive but not as
reactive as alkali metals Color of silver Higher Density than Alkali
metals It is more difficult for
atoms to give two atoms than to give one when joining with other atoms.
often mixed with Aluminum- forms strong/light weight
alloys
magnesium
Magnesium
Used to make steel (light metal w/o losing strength)
photosynthesis (chlorophyll)
Calcium bones & teeth Chalk, limestone,
pearls, plaster
Label the Alkaline Earth Metals to your PT
Write what you have learned today about how
the groups of elements on the periodic table are grouped?
K-W-L
Boron Family (13)
Group contains: one metalloid and 4 metals
3 VE Reactivity: reactive Solids at room
temperature
Boron (metalloid) Hard/brittle never found pure in
nature in borax...used to make
detergents & cosmetics
Aluminum Most common most abundant
metal in earth’s crust
important metal for industry light, strong, slow
to corrode
A coating of aluminum oxide is what makes us able to use this highly reactive metal
Boron Family
13
Al
Aluminum26.9
8
Aluminum
Label the Boron Family on your PT
Carbon Family (14)
- Group contains: one nonmetal, two metalloids, and two metals
- 4 VE- Can gain 4 e-, lose 4
e-, or share e-- Reactivity: varies- Can be found
uncombined or in compounds
silicon
Most compounds in the body contain Carbon
The metalloids Si and Ge are used to make computer chips.
Si 2nd most abundant element in Earth’s crust
Si used to tip saw blades
The metal Tin (Sn) is useful because it is not very reactive.
For example, a tin can is really made of steel coated with tin.
Because the tin is less reactive than steel is, the tin keeps the iron in the steel from rusting.
Label the Carbon Family on your PT
Nitrogen Family (15)
- Group contains: two nonmetals, two metalloids, one metal
- 5 VE - Tend to gain 3 electrons- Reactivity: varies- Solids at room
temperature except for Nitrogen
- N and P used in fertilizers- P on tips of matches
Arsenic
Nitrogen makes up 80% of the air you breathe.
Nitrogen is not very reactive, however, Phosphorus is.
Label the Nitrogen Family on your PT
Oxygen Family (16)- Group contains: three nonmetals, one metalloid,
and one metal- 6 VE- Tend to gain 2 e-- Reactivity: Reactive- All but Oxygen are solids at room temperature- O very abundant element- S used in fertilizers- O makes up 20% of air we breathe
sulfur
Label the Oxygen Family on your PT
Halogen Family (“salt-former”) (17)
-Group contains: nonmetals-7 VE-Reactivity: very reactive
-they only need to gain one electron-poor conductors-violent reactions with alkali metals to
form salts-never in uncombined form in nature-F most active halogen-Although the chemical properties of
halogens are similar, the physical properties are quite different.
F compounds in toothpaste Cl kills bacteria I keeps thyroid gland
working properly
Halogens cont… bromine
Label the Halogen Group on your Periodic Table
The Noble Gases (Inert Gases) (18)-Group contains: nonmetals
- Reactivity: non-reactive 8 VE They are full so they do not
need to lose or gain any electrons.
Normally, they do not react with other elements.
colorless, odorless gas at room temperature
In “neon” lights- in earth’s atmosphere (less
than 1%)
Neon
Label the Noble Gases on your Periodic Table
Hydrogen
Electrons in the outer level: 1 Reactivity: reactive Colorless, odorless gas at room temperature Low density Explosive reactions with oxygen
They properties of hydrogen do not match the properties of any single group, so hydrogen is set apart from the other elements.
It is above group 1 because atoms of the alkali metals also have only one electron in their outer level.
Atoms of hydrogen can give away one electron when they join with other atoms.
It’s physical properties are like those of nonmetals. Hydrogen is the most abundant element in the
universe.
Transition Metals (3-12)
Group contains: metals Electrons in the outer level: 1 or 2 Reactivity: less reactive than alkaline-earth
metals Shiny Good conductors Higher density and melting points than Groups
1 and 2 (except for Mercury) Fe, Co, and Ni produce magnetic field
mercury
Groups 3-12 do not have individual names. Instead they are called transition metals. They do not give away their electrons as
easily as Group 1 and Group 2 do. Transition metals are less reactive than alkali
metals and alkaline-earth metals.
Label the Transition Metals on your periodic table
Lanthanide series (period 6) Actinide Series (period 7)
Separated from table to make easy to read/print
silver, silvery-white, or gray metals. Conduct electricity
Rare Earth Elements
uranium
1st row Shiny, reactive metals Used to make steel
Lanthanide
Label the Lanthanide Series on your PT
2nd row All are radioactive or unstable These can be made in labs. Some of these do
not exist in nature.
Actinide
Label the Actinide Series on your PT
Alkali metals (Group 1) are the most reactive
metals. Atoms of the alkali metals have one electron
in their outer level.
Summary
Alkaline-earth metals (Group 2) are less
reactive than the alkali metals are. Atoms of the alkaline-earth metals have two
electrons in their outer level.
Summary
Transition metals (Groups 3-12) include most
of the well-known metals and the lanthanides and actinides.
Summary
Groups 13-16 contain the metalloids and some
metals and nonmetals.
Summary
Halogens (Group 17) are very reactive
nonmetals. Atoms of the halogens have seven electrons in
their outer level.
Summary
Noble gases (Group 18) are unreactive
nonmetals. Atoms of the noble gases have a full set of
electrons in their outer level.
Summary
Hydrogen is set off by itself in the periodic
table. Its properties do not match the properties of
any one group.
Summary
Grouping the Elements
Directed Reading B
Placing All Your Elements on the Table
Reinforcement Worksheet
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