Download Chapter 5 Organizing The Elements

Chapter 5 Organizing The Elements
OBJECTIVES
• Describe how Mendeleev arranged the elements in his table
• Explain how the predictions Mendeleev made and the discovery of new elements
demonstrated the usefulness of his periodic table
• Describe the arrangement of elements in the modern periodic table
• Explain how the atomic mass of an element is determined and how atomic mass units
are defined
• Identify general properties of metals, nonmetals, and metalloids
• Describe how properties of elements change across a period in the periodic table
• Relate the number of valence electrons to groups in the periodic table and to properties
of elements in those groups
• Predict the reactivity of some elements based on their locations within a group
• Identify some properties of common A group elements
• In 1750 scientists had identified only ____elements most of
these were metals
• As the number of identified elements grew so did the need for
organization
• In 1789 Antoine Lavoisier grouped elements according to
categories called______, non-metals, ______and earths
• In 1860 Mendeleev (Russian) needed to describe the now known 63
elements to his students
• On cards, he listed the name, mass and properties of the 63 elements
• He arranged them in order of increasing atomic mass. He was able to
break the elements into _____(see pg 127 Fig. 3 and _______based on the
properties of the elements
• Columns increased from ___to _________He knew that not all
elements were discovered yet so he left room for them
• Properties of elements are related to its location in the table
• Review questions 1-5 pg. 129
5.2 Modern Periodic law
• In the modern periodic table, elements are arranged by __________ATOMIC
NUMBER (number of protons)
• PERIODS
• Each _____in the periodic table is a _________Ex. Period 1 has 2 elements period 2
and 3 have 8 elements
• The number of elements in each ________varies because of the available orbitals
increase from energy level to energy level
• In other words---------the _____energy level has only __orbital so, the 1
electron in a H atom and the __electrons in a He atom can fit in this
orbital
• But Li contains ___ electrons---------so __ can fit in the 1st orbital and the
other _________has to go in the 2nd orbital(or energy level) this is why Li
is the first element in Period 2
• Na (sodium) the first element in ______3 has one _______in its 3rd orbital
or energy level
• K (potassium), the first element in Period 4 has ___electron in its 4 th
orbital
• This pattern applies to all ________ in the first column on the table
•
•
•
•
•
GROUPS (FAMILIES)
Each _______is called a group or family
The _________within a group have ________properties (electron configurations)
The electron _______________determines the __________properties
THE PATTERN OF REPEATING CHEMICAL PROPERTIES IS CALLED
_________ ___________REFER TO FIG. 7 PGS 132-133
•
•
•
•
Atomic Mass
Copy Fig. 8 into your notebook
There are 4 pieces of information for each element
________of the element, its_______, its atomic________, and its atomic
_____(the number of isotopes and their mass in nature)
• Atoms of 2 isotopes have different _________masses(isotopes have
different # of neutrons than protons) they are usually equal
Classes of Elements
• Solids, _______, gases based on their state at room temperature
• Symbols solids (black) liquid (purple) gas (red)
• Elements are divided into those that occur __________and those that do
not
• Ex. Elements with an atomic number of ___ or above DO NOT OCCUR
NATURALLY
• _______occur naturally
•
•
•
•
Third classification is based on general properties
____________located on left (blue)
___________located on right (yellow)
____________located in the middle (green)
•
•
•
•
•
•
•
•
METALS
_____________of elements are metals
Represented by blue boxes
Good _____________of heat
Electric current
_________at room temperature (except mercury)
Most are malleable
Many are ___________(able to be drawn into thin wire)
• Groups 3 through 12 are referred to as ___________metals
• These transition metals form a bridge between the elements on the
_____and _______One property of these metals is their ability to form
_______________with distinct colors
• Ex. Tinted glass
• They are among the 1st elements discovered
•
•
•
•
•
•
•
NONMETALS
Represented by yellow boxes
Have properties __________to those of _________
______conductivity of heat and electric
Low _________points
Many are ________at room temperature
Are brittle (will shatter or crumble)
• METALLOIDS
• Represented by green boxes
• Properties of these elements fall somewhere _________metals and
nonmetals
• Their ability to conduct heat or electric depends on their temperature
Variation across a Period
• Changes in the properties of elements change in a similar way when you move from
_______to ______(except for period 1)
• From left to right, elements become ______metallic and ______nonmetallic
• Most _____________elements or on the left side of the table
• Most reactive ___________are on the right side (group 17)
• Copy fig. 13 into your notebooks
• Complete questions 1-5 and 7
•
•
•
•
Valence electrons
An electron that is in the _______occupied energy level of an atom
Valence electrons play a key role in chemical _________
The properties of elements vary because the ______of valence electrons
___________from left to right
• Remember that elements in a group have _______properties
because they have the same number of _________electrons
• Ex. Hydrogen and Lithium have I valence electron
• Alkali metals
• elements in group 1A
1 valence electron
• Highly __________
• Ex. Sodium chloride (table salt)
• Group 1A Li, Na, K, Rb, Cs, Fr
• Their reactivity increases from ______TO BOTTOM
•
•
•
•
•
Alkaline Earth metals
Group 2A
Contain ___ valence electrons
_________than metals in group 1A
Differences in reactions with water
• Calcium and magnesium are essential to ____________functions
• Magnesium
• Key role in _________________ Mixture of magnesium and other
metals can be as strong as _________but much lighter
• Calcium
• Keeps bones and teeth strong, toothpastes may contain calcium to polish
teeth
• Plaster casts contain calcium sulfate
•
•
•
•
•
The Boron Family
Group 3A
Contain ____valence electrons
Aluminum(metal) most __________metal in the earth’s crust
Boron(metalloid)
•
•
•
•
•
•
•
The Carbon Family
Group 4A
_____valence electrons
Contains 1 nonmetal(carbon)
2 metalloids(silicon, germanium)
2 metals(tin, lead)
Life on earth would not ______without______, most compounds in your body contain
carbon
• Silicon is the ____ most abundant element in the crust
•
•
•
•
•
•
•
•
•
The Nitrogen family
Group 5A
Contain ___ valence electrons
Contain 2 nonmetals(arsenic, antimony)
1 metal(bismuth)
1 nonmetal gas (nitrogen)
1 solid nonmetal(phosphorus)
In this group ____________and _________are most important
Contained in fertilizers and compounds in your body to release energy
• The Oxygen family
• Group 6A
• Contain ___ valence electrons
•
•
•
•
•
3 nonmetals (oxygen, sulfur, selenium)
2 metalloids (tellurium, polonium)
Oxygen is the _____abundant element in the earth’s crust
Can be stored as a liquid, under pressure
___________is another form of oxygen ground level is an eye irritant, in the
atmosphere absorbs _____________
•
•
•
•
•
•
•
•
The Halogens
Group 7A
___valence electrons
Highly _________nonmetals
2 gases (fluorine, chlorine)
1 liquid (bromine)
1 solid (iodine)
All react easily with most ______
• Fluorine compound used to prevent tooth decay, non-stick coatings
• Chlorine is in bleach, and used to kill bacteria in drinking water and pools
(bromine for hot tubs)
• Your body needs iodine to keep your thyroid gland working properly
•
•
•
•
The Noble Gases
Group 8A
____valence electrons (except helium) (2)
This means these elements have a ____outer ______This group does not react with
any other ________
• Questions 1-10 page 145
• Internet activity—see if you can find the 25 essential elements to the human body and
3 elements that should be avoided completely