the most important tool in chemistry that is useful for understanding and predicting properties of elements
Periodic table
Russian chemist and teacher that published a periodic table in which the elements were arranged in 1869
Dimitri Mendeleev
1. In order of increasing atomic mass
2. In horizontal groups containing elements with similar properties
3. Left spaces in his periodic table so that elements with similar properties could be place in the same group (see Figure 6.3 page 156)
4. In 1875 and 1886 gallium and germanium were discovered and two empty spaces in the table were filled
2. In horizontal groups containing elements with similar properties
3. Left spaces in his periodic table so that elements with similar properties could be place in the same group (see Figure 6.3 page 156)
4. In 1875 and 1886 gallium and germanium were discovered and two empty spaces in the table were filled
How was the periodic table arranged?
in order of increasing atomic number and in vertical groups containing elements with similar properties
How are elements arranged in the modern periodic table?
○ States that when elements are arranged in order of increasing atomic number there is a periodic reputation of physical and chemical properties
Periodic law
metals, nonmetals, metalloids metals
What three class can the periodic table be divided into?
good conductors of heat and electricity, ductile, are malleable into thin sheets, and are solids at room temperature
metals
placed in the upper right corner of the periodic table, and tend to have properties which are opposite of those of metals
Nonmetals
have properties similar to metals and nonmetals
Metalloids
Noble bases
representative elements
transition metals
inner transition metals
representative elements
transition metals
inner transition metals
what four categories according to electron configuration can elements be classified in?
Have their outermost s or p sublevels filled and do not participate in many chemical reactins
Noble bases (Group 8A)
– Have their outermost s or p sublevels only partially filled (see 164)
– Display a wide range of physical and chemical properties
– Group 1A is called the alkali metals – Group 2A is called the alkaline earth metals
– Group 7A is called the halogens
– Their group number equals the number of electrons in the highest occupied energy level
– Display a wide range of physical and chemical properties
– Group 1A is called the alkali metals – Group 2A is called the alkaline earth metals
– Group 7A is called the halogens
– Their group number equals the number of electrons in the highest occupied energy level
Representative elements (Groups 1A through 7A)
alkali metals
Group 1A
alkaline earth metals
Group 2A
halogens
Group 7A
Representative Elements
Which group number equals the number of electrons in the highest occupied energy level?
Transition metals
B Group
Transition metals
Outermost S and nearby D sub level contain electrons
Transition metals
Are characterized by the presence of electrons in d orbitals & made up of the d block
Inner Transition Metals
Their outermost s and nearby f sublevel contain electrons
– Are characterized by the presence of electrons in the f orbitals
– Make up the f block
– Make up the f block
Are characterized by the presence of electrons in the f orbitals & Make up the f block
block diagram
Consists of four blocks- s p d f and Each block corresponds to a sublevel being filed with electrons
Periodic table
How can electron configurations be determined?
left to right and top to bottom
How do you read the Periodic table?
the principal energy level
What do period numbers correspond to?
one less
The principal energy level of the d sublevel is ____________ than the period number
two less
The principal energy level of the f sublevel is _________ than the period number
Atomic radius
What cannot be determined directly from a single atom because an atom doesn’t have a sharply defined boundary?
Atomic radius
What is one- half of the distance between the nuclei of two like atoms which one joined?
Atomic Radius
Measured in pecoimeters
an atom or group of atoms that have a positive or negative charge
What is an ion?
form + ions called cations by losing one or more electrons from their highest occupied energy level
What do Atoms of metals Tend to form?
form negative ions called anions by gaining one or more electrons
What do Atoms of nonmetals tend to form?
Energy required to remove an electron from a gaseous atom
What is Ionization Energy?
Decreases as you go down a group because the size of the atom increases as you go down a group
Does the first ionization energy increase or decreases as you go down a group? Why?
Increases as move from left to right across a period this is because the size of the atom decreases
Does the first ionization energy increase or decreases as you move from left to right across a period? Why?
Positive ions are always smaller than the neutral atoms from which they are formed
What is the Ion Size of Positive ions?
Negative ions are always larger than the neutral atoms from which they are formed
What is the size of negative ions?
It is the ability of an atom in a compound to attract electrons
What is Electronegativity?
decreases
Electronegativity ______ as you move down a group
Increases
Electronegativity ____ as you move left to right in a period
Atomic radius and ionic size
As you go left to right which decrease?
Ionization energy and electronegativity
As you go left to right which increase?
Atomic radius and ionic size
As you move down which increase?
Ionization energy and electronegativty
As you move down which decrease?
13
How many elements had been identified by the year 1700?
Chemists began to use scientific methods to search for elements
What caused the rate of discovery to increase after 1700?
Chemists used the properties of elements
What did chemists use to sort elements into groups?
A russian chemists and teacher who developed a periodic table
Who was Mendeleev?
in order of increasing mass
What property did Mendeleev use to organize the elements into a periodic table?
the properties of undiscovered elements
What did he use his periodic table to predict?
in increasing atomic number
How are the elements arranged in the periodic table?
when elements are arranged in order of increasing atomic number there is a periodic repetition of physical and chemical properties
What does the periodic law state?
Yellow= metals
blue= nonmentals
green= metalloids
blue= nonmentals
green= metalloids
Explain the color coding of the squares in the periodic table
Metal
nonmetal
nonmetal
Under some conditions a metalloid may behave like a _____. Under other conditions, a metalloid may behave like a _____
name
symbol
atomic number
average atomic mass
state at room temp
electrons in each energy level
weather an element is found in nature
symbol
atomic number
average atomic mass
state at room temp
electrons in each energy level
weather an element is found in nature
List six things you can discover about an element using a periodic table
electrons
What are the subatomic particles that play the key role in determining the properties of an element?
Exhibit a wide range of physical and chemical properties
Why are Group A elements called representative elements?
alkali metal
sodium
halogen
chlorine
alkaline earth metal
calcium
halogen
fluorine
noble gas
xenon
alkali metal
potassium
alkaline earth metal
magnesium
3
How many electrons are in Group 3A?
1
How many electrons are in group 1A
8
How many electrons are in group 8A
s or p sublevels are filled
Noble gases
s or p sublevels are only partially filled
Representative elements
s sublevel and nearby d sublevel contain electrons
Transition metals
s sublevel and nearby f sublevel contian electrons
Inner transition metals
Groups 3A 4A 5A 6A 7A and 8A except for helium
elements found in the p block
argon
Noble Gases
gallium
Representative elements
vanadium
Transition metals
nobelium
inner transition metals
The atomic size increases within a group as atomic number increases. The atomic size decreases from left to right across a period
What is the general trend in atomic size within a group? Within a period?
the charge on the nucleus
the number of occupied energy levels
the number of occupied energy levels
What are the two variables that affect atomic size within a group?
when electrons are transferred between atoms
How are ions formed
cation
What is an ion with a positive charge called
anion
What as an ion with a negative charge called
negative
What is the charge of Anion
positive
What is the charge of cations
nonmetal
Is an Anion a metal or nonmetal
metal
is a cation a metal or nonmetal
plus
Is an Anion a plus or minus sign
minus
Is a cation a plus or minus sign
Atomic size increases from top to bottom within a group/ The nuclear charge has a smaller effect on the electrons in the highest occupied energy level and less energy is required to remove an electron
Why does ionization energy tend to decrease from top to bottom within a group?
The nuclear charge increases across a period but the shielding effect remains constant there is greater attraction of the electrons to the nucleus and more energy is required to remove an electron
Why does ionization energy tend to increase as you move across a period?
An ion with a 2+ charge
There is a large increase in ionization energy between the second and the third ionization energies of metal. What kind of ion is the metal most likely to form?
lose
positive
positive
Metallic elements tend to _______ electrons and form ______ ions
gain
negative
negative
nonmetallic elements tend to _____ electrons and form ______ ions
transition metals
are located only on the right side of the periodic table
Inner Transition Metals
are located on the bottom of the periodic table
Representatives Elements
are located on the right and left side of the periodic table
Representative Elements
Group A elements
Transition Metals
Group B elements
Noble Gases
Pd and Ag
Noble gases
Kr and Xe
…
Pm and Sm
Representative Elements
Li and B
Noble gases
Contain only nonmetals in the gas phase
Representative Elements
Contain only nonmetals in the gas, liquid and solid phase
a periodic repetition of their physical and chemical properties
What pattern is revealed when the elements are arranged in a periodic table in order of increasing atomic number
Yes they are both in Group 4A and each have four electrons in highest occupied energy level
Based on their locations in the periodic table would you expect carbon and silicon to have similar properties?
nonmetal
a gas at room temp
nonmetal
brittle
metal
malleable
nonmetal
poor conductor of electric current
metal
shiny
they have properties that are similar to those of metals and nonmetals. How a metalloid behaves depends on conditions
How are metalloids different from metals and nonmetals
1A 2A 7A 8A
Where are the alkali metals alkaline earth halogens and noble gases on periodic table
helium
which noble gas does not have eight electrons in its highest occupied energy level
The first ionization energy is the energy needed to remove a first electron from an atom. The second is the energy needed to remove a second electron.
Explain the difference between the first and second ionization energy
