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