Chapter 2 - Periodic Table Flashcards
The first version of the periodic table of the elements was published by who? What did he order them with? And what are they now ordered by?
Dmitri Mendeleev, he ordered them according to atomic weight
Since then Henry Moseley revised it organizing elements based on increasing atomic number rather than atomic weight
What does the periodic law say?
The chemical and physical properties of the elements are dependent, in a periodic way upon their atomic numbers
The modern periodic table is arranged how? (Laterally and vertically)
With periods (rows), and groups or families (columns)
There are 7 periods, what does this represent?
The principal quantum numbers n1-n7
Groups contain elements that have similar…
Electronic configuration in their valence shell and share similar chemical properties
What does the Roman numeral above each group represent?
The number of valence electrons that the element has in that group when in a neutral state
Letters A and B separates the elements into 2 larger groups, what else is A and B elements called?
A elements are known as representative elements
B elements are known as nonrepresentative elements
What groups are in the A elements? What are their subshells?
Includes groups IA-VIIIA, have either S or P subshells
What groups of elements are in B elements? What are their subshells?
Include both the transitional elements (subshells s, and d), and the actinide and lanthanide series (subshells s, and f)
For A and B elements what does it tell you about their electron configuration?
For A (representative elements) the Roman numeral and the letter designation determine the electron configuration
For B (nonrepresentative elements) they may have unexpected electron configuration
What 3 groups of elements can the periodic table be divided into with similar characteristics?
Metals, nonmetals, metalloids (semimetals)
Where are metals found on the periodic table and what series’s do they include?
Left side and middle of periodic table
Include active metals, transition metals, actinide, and lanthanide series
Metals are generally what?
Lustrous (shiny) solids, have high melting points, and density
Metals have the ability to…
Be deformed without breaking
Be hammered into shapes (called malleability)
Be pulled or drawn into wires (called ductility)
At an atomic level metal is defined by…
A low effective nuclear charge, low electronegativity (high electropositivity), large atomic radius, small ionic radius, low ionization energy, and low electron affinity (easily give up electrons)
Many of the transition metals have 2 or more oxidative states meaning
Charges when forming bonds with other atoms
Why are metals good conductors of heat and electricity
Because valence electrons of metals are loosely held to their atoms, letting them move freely
Active metals are found in what subshells?
S subshells
Where are nonmetals found on the periodic table?
Upper right side
List as many characteristics of nonmetals as you can
-Generally brittle in the solid state
-Show little or no metallic luster
-Have high ionization energies, electron affinities, and electronegativity
-small atomic radii and large ionic radii
-usually poor conductors of heat and electricity
-Inability to easily give up electrons
-less unified in their chemical and physical properties than the metals
What seperates metals and non metals?
Metalloids
Name all the nonmetals and what is the group known as
Known as a stair step group of elements
Includes: Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), polonium (Po), and astatine (At)
Characteristics of metalloids
-Electronegativities and ionization energies of the metalloids lie between those of metals and non metals
-Physical properties, densities, boiling points, melting points vary widely
-Reactivities of the metalloids are dependent on the elements with which they are reacting (can act as metal or nonmetal)
The electrostatic attraction between the valence shell electrons and the nucleus is know as…
The effective nuclear charge (Zeff) - a measure of the net positive charge experienced by the outermost electrons
On the periodic table how does Zeff increase?
It increases up and to the right
What group are the noble (inert) gases
Group 18
When do elements tend to be most stable?
When valence shell is full
On the periodic table where does atomic radius increase?
Going down and to the left
Out of metals and non metals which ones tend to gain or lose electrons?
Metals lose electrons and become positive while nonmetals gain electrons and become negative
Metalloids can go either way but tend to follow the trend based on what?
Which side of the metalloids line they fall on
Do nonmetals closer to the metalloid line poses a larger or smaller ionic radius than their counterparts closer to group 18?
Larger
Is the ionic radius of metals near the metalloids line smaller or larger than other metals?
Smaller
Ionization energy is also known as
Ionization potential
What is ionization energy?
The energy required to removed an electron from a gaseous species
Removing an electron from an atom always required a input of heat, making it what type of process?
Endothermic process
The greater the Zeff of an atom correlates how to ionization energy?
The greater the Zeff the more tightly bound they are, making it more difficult to remove one or more electrons, this increases the ionization energy
On the periodic table where does ionization energy increase?
Up and to the right
Energy necessary to remove the first electron and second electron are called what?
The first and second ionization energy
What group is least likely to give up an electron
The noble or inert gases (group 18)
What group is the most greedy group for electrons?
The halogens (group 17)
What process expels energy in the form of heat
Exothermic processes
What is electron affinity?
The energy dissipated by a gaseous species when it gains an electron - opposite concept of ionization energy
Exothermic processes have a negative sign but the electron affinity is reported as a positive number, why is this?
Because it is the sum of dissipated energy
The higher electrostatic pull is equal to
Higher Zeff or effective nuclear charge
The stronger the electrostatic pull between the nucleus and the valence shell equals greater energy release when the atoms gain an electron. Why is this?
This is because the electron has to overcome a stronger attraction from the nucleus to be added to the atom’s electron cloud.
Where on the periodic table does electron affinity increase?
Up and to the right
Those with lower electron affinities are less likely to what?
Gain an electron
What group has the lowest electron affinity?
The noble gases. This is because they have full electron shells and are highly stable, so they are generally not inclined to gain or lose electrons.
What is electronegativity?
The measure of the attractive forces that an atom will exert on an electron in a chemical bond
The greater the electronegativity of an atom the greater it attracts electrons within a bond
What is the main exception to the electronegativity trend on the periodic table?
The noble gases, specifically the first 3 because they do not often form bonds
What does the Pauling electronegativity scale range from on elements? (Highest and lowest)
.7 for Cesium (least electronegative) to 4.0 for fluorine (most electronegative)
What is the trend for increasing electronegativity on the periodic table?
Up and to the right
What are the trends for the periodic table for electronegativity, atomic radius, ionization energy, and electron affinity
Electronegativity, ionization energy, and electron affinity increase up and to the right on the periodic table
Atomic radius increases down and to the left on the periodic table
What is the name of group 1 on the periodic table?
Alkali metals
List some characteristics of alkali metals?
-Densities are lower than those of other metals
-Have one loosely bound electron in their outermost shells
-React readily with nonmetals-especially halogens
What is the name of group 2 on periodic table?
Alkaline Earth metals
Together group 1 and group 2 on the periodic table are called…
Active metals because they are so reactive that they are not naturally found in their elemental (neutral) state
Characteristics of alkaline earth metals valence electrons?
They have 2 electrons in their valence shell, both of which are easily removed to form divalent cations
Group 16 on the periodic table is called what?
The Chalcogens
Even though Chalcogens are very biologically useful, at high concentrations they can be…
Toxic or damaging
What is the name of group 17 on the periodic table?
The Halogens
Characteristics of Halogens
Highly reactive nonmetals
Desperate to complete their octet by gaining one additional electron
Are so reactive that they are not naturally found in their elemental state but rather as ions called halides
What element has the highest electronegativity?
Fluorine (F)
What are noble gases also called?
Inert gases
Why do noble gases have minimal chemical reactivity?
Because of their filled valence shells
Noble gasses characteristics
Extremely low boiling points
Exist as gases at room temperature
Why are transition metals good conductors?
Due to their loosely held electrons that progressively fill their d-orbitals in their valence shell
Many of the transition metals can have different possible charged forms or oxidation states because of what?
Their capability of losing different numbers of electrons from the s and d orbitals in their valence shell - this forms many different ionic compounds
For transition metals formation of complexes causes the d-orbitals to split into energy sub levels, enabling…
Many of the complexes to absorb certain frequencies of light, frequencies not absorbed give the complexes their characteristic colors, giving way to electron transitions
When we perceive an object as a particular color, it is because that color is not absorbed but rather…
Is the color Reflected by the object
If an object absorbs a given color of light and reflects all others how does our brain arrive at a perception of color?
Our brain mixes these subtraction frequencies and we perceive the complementary color of the frequency that was absorbed
What groups on the periodic table are most reactive with water
Groups 1 and 2
What groups have 6 valence electrons
6, and 16
What groups contain atleast 1 metal?
Groups 1-15
All groups contain multiple oxidative states but most notably what groups do?
3-12 (transition metals)
All groups have negative oxidative states but most notably…
Groups 14-17
