Periodic Trends Flashcards
___________ discovered that each element has a unique atomic number (z)
Moseley
Electronegativity increases
Up and to the righteous
Size increases
Down and to the left
Effective nuclear charge (Zeff)
The attraction between a nucleus and the valance electrons.
The nucleus is shielded from the valance elections by the
Inner electrons (s)
Effective nuclear charge =
Atomic number - inner electrons
Effective nuclear charge increases
From left to right
Cations are always smaller than their parent atom because
Cations lose electrons and therefore lose an energy level
Why are anions always larger than its parent atom
Because repulsion between electrons become greater when outer shell is completed, therefore making it swell and become bigger
Ionization energy
Energy required to remove an electron from an atom in the gas phase
Electronegativity
A measure of an atoms attraction to an electron
Electron affinity
The energy released when an atom gains an electron in the gas phase to form a negative ion
Ionization energy equation
X -> x+ + e-
Electron affinity equation
X+e- = x-
Bonding atomic radious is equal to
Half the distance between two bonded nuclei
Metals tend to ______ electrons and become ______________
Lose; cations
Nonmetals tend to _____ electrons and become ______________
Gains; anions
Isoelectronic series
A group of ions all containing the same number of electrons
Metallic character increases
Down and to the left
Group 1a
Alkali metals
Group 2a
Alkaline earth metals
Group 7a
Halogens
Metals
Listed good conductors of heat and electricity and malleable and ductile
No metals
No list or poor conductors and nonmalleable
Metalloids
Luster but brittle
Nonmetal oxides
Carbon Nitrogen Phosphorus Sulfur (Plus oxygen)
Metal oxide + water =
Base (metal hydroxide)
Metal oxide + acid =
Salt and water
Nonmetaloxide and water=
Acid
Nonmetal oxide and base=
Salt and water
Bigger compounds have ______ boiling points
Higher
As an atoms radius decreases to
Ionization energy increases
Mendeleev and Meyer arranged the table based on
Chemical similarities
