Unit 4: The Periodic Table Flashcards
electronegativity
tendency for the atoms of the elements to attract electrons during chem. reactions.
the pauling scale relies on what two factors?
ionization energy and electron affinity
ionization energy
the amount of energy needed to remove the highest energy electron from an element in its GASEOUS PHASE
electron affinity
the change in energy when an electron is added.
electroegativity trends in groups
electronegativity decreases down a group, because PEL’s are added going down a group which creates a greater atomic radius, decreasing the nuclear attraction that would increase electronegativity.
shielding
the buffering of attraction between the positive nucleus and the outermost electron shell.
electronegativity with noble gases
they do not have electronegativity values because they were historically thought to not bond, and even though they sometimes do, no values were assigned anyways.
electronegativity trends down a period
from left to right, electronegativity increases, since the valence electrons become more full, making it easier to gain electrons to fill up the shell, and atomic radius decreases as the nuclear attraction increases.
What is the element with the lowest electronegativity?
cesium, with only 1 valence electron and the largest atomic radius
what is the element with the highest electronegativity
fluorine, small atomic radius and high # of valence electrons.
cation
atom that loses electrons, a positively charged ion.
what kind of elements form cations?
metals since they have leses valence electrons, easier to lose than gain to create a full octet/duet.
Is a cations radius smaller or larger than the original atoms?
the radius is smaller, since the loss of the electron results in less shielding, making the attraction from the nucleus pull the electrons closer to the atom.
anion
atom that has gained an electron, negatively charged
what kinds of elements form anions?
nonmetallic anions, bc they have high ionization energies and readily gain electrons
is the radius of an anion larger or smaller than that of the original atoms?
larger, because the addition of the electron makes the atom bulge due to electron-electron repulsion
metalliods/semimetals
elements with properties between or in combination of those of nonmetals and metals.
what are the six metalloids?
boron, silicon, germanium, arsenic, antimony, tellurium BATGAS
what is the only metal that is liquid at STP?
mercury
what is the only nonmetallic element that is liquid at STP?
bromine
what are the only two elements on the periodic table that are liquid at STP?
bromine and mercury
what is considered the most metallic element, chemically?
cesium (since francium is radioactive) because it has only one v-electron, has the largest radius due to many PELs, which causes shielding, and the lowest ionization energy.
what group is the most reactive metallic elements?
alkali metals
what is considered the most chemically nonmetallic element?
fluorine, since it has the smallest radius of all group 17 elements and only has 1 missing v-electron, allowing it to be the most attractive element.
what are the most reactive non metallic elements?
group 17 halogens, who react with alkali metals, combining to form salts
which group 18 elements have some chemical reactivity?
Xenon and Krypton have oxidation states other than 0, though noble gases all have full valence shells and are very stable as a result, and so usually will not bond.
name the monatomic elements
group 18 noble gases
name the diatomic elements
H O F Br I N Cl
name the five elements that are gases at STP besides the noble gases
hydrogen, nitrogen, oxygen, fluorine, and chlorine. (the diatomic elements minus iodine and boron)
after which number element are all elements considered naturally occurring radioactive isotopes?
83
allotropes
2 or more different molecular forms of the same element in the same physical state
name the two allotropes of oxygen
ozone (O3) and oxygen gas (O2)
name the three allotropes of carbon
diamond, graphite, and buckminsterfullerenes (C-60)
atomic radius
half that distance between the nucleus of the 2 bonding atoms.
measuring atomic radius
cannot be measured directly since atoms do not have defined boundaries, though there are many ways to estimate
what are the two ways to estimate atomic radius?
- using X-ray diffraction if the element is a solid, crystalline structure, to estimate the distance between nuclei.
- for diatomic elements it is only possible to estimate the distance between the nuclei of the two bonded atoms.
atomic radius trends down a group
atomic radius increases as you go down a group, bc more PEL’s are being added, increasing shielding as well.
atomic radius trend across a period
generally decreases since the PEL remains the same while more and more v-electrons are added, increasing the NUCLEAR CHARGE while the shielding stays the same.
in a single period, atomic radius and atomic number have an
INVERSE RELATIONSHIP
when a substance is ionized it results in a…
1+ charge
why are there jumps in ionization energy?
valence electrons are easy to take away, so they require low amounts of ionization energy to be stolen. Once they are all gone, it takes much more energy to take away a core electron, which accounts for the jump.
what is the unit for ionization
kj/mol
what element has the highest first ionization energy?
helium, because it has both a full electron shell and also the smallest atomic radius, which separates it from the rest of the noble gases, since a smaller radius = greater attraction = harder to steal the electron
ionization group trends
as atomic # increases in group the ionization energy decreases, since the PELs increase, increasing shielding, which makes it easier to steal the electron.
ionization trends across a period
first ionization energy increase across a period, since the nuclear charge increases, strengthening the hold on the electrons.
which subatomic particle effects chemical and physical properties the most?
the electron
the arrangement of the periodic table is related to
electron configuration
what are the four categories electrons can be classified into based on electron configuration?
noble gases, rep. elements, transition metals, and inner transition metals.
electron confg: noble gases
they have a full outer shell and are inert gases bc they do not bond, belonging to block p except for Helium, which is in the s block.
electron config: representative elements
- elements with outermost p and s sublevels only partially filled
- group number tells you the number of valence electrons
- the representative element group names are the alkali metals, alkaline earth metals, and the halogens.
electron config: transition metals
- group B elements
- contains 3s elements
- defined as the elements with an incomplete d orbital.
- belongs to the d sublevel block but not all d-block elements are transition metals
- electrons are added to the d sublevel rather than the outermost shell, disrupting the pattern
- transition metals fill the PEL one less than the period number.
electron config: inner transetals
- the lanthanides and actinide series, belonging to the F sublevel, where electrons are added to the f shell rather than the outermost shell and the PEL added to is 2 less than the period.
electrno config: lanthanides
electrons are added to 4f
electron config: actinides
electrons added to 5f
dmitri mendeleev (1843-1907)
- mid 1800s arranged elements in vertical columns with increasing atomic mass, arranged by chem. and physical properties
- blank spaces were from undiscovered elements
- he could predict properties by comparing to the known elements.
henry mosely (1887-1915)
- determined nuclear charge of the atom, aka the atomic #
- arranged the table according to atomic # like the modern periodic table.
periodic law
when elements are arranged in order of increasing atomic number, there is a periodic pattern of chemical and physical properties
what kinds of elements form compounds and solutions with COLOR
transition metals
what kinds of elements have MULTIPLE oxidation states
transition metals
name the four properties of metals
- malleable
- ductile
- luster
- good conductors of both heat and electricity
ductile
can be made into wire
luster
ability to reflect light
group 1 metals are so reactive that you will never find them _____ in nature, only in the form of _____
free, salts
how do you extract the group 1 element from the compound
run electric current through it, Cl gas for example will evaporate and leave behind the group 1 element.
