Periodic Trends Flashcards
Periodic Law
Chemical and physical properties of the elements are dependent, a perioid way upon their atomic numbers
Elements in a group share the same ______________
electron configuration in their valence shell and share similar similar chemical properties
How do you tell how many valence electrons are there for an atom?
the Roman Numeral
for A elements: whatever the element is = your valence electrons (they are called representative elements) their valence electrons are in the s or p subshell)
for B elements: unexpected configurations
Another names for groups (columns)
Families
Period
Rows
Groups
Columns
A elements
Representative elements, groups IA through VIIIA
Group B elements
Non representative elements and include both transition elements, lanthanide and actinide, have 2 or more oxidation states (charges when forming bonds with other atoms)
Metal
lustrous shiny solids except mercury, generally high melting points and densities except lithium (other exceptions), deformed without breaking
at the atomic level, a 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
all of these qualities are manifestations of the ability of metals to easily give up electrons
Describe Ductility.
metals ability to be pulled or drawn into wires
Describe malleability.
Metals ability to be hammered into shapes
Groupe B transition metals have
Two or more oxidation states (charges when forming bonds with other atoms)
Metals are good conductors because
the valence electrons of all metals are only loosely held to their atoms, therefore they are free to move making metals good conductors of heat and electricity
Valence electrons of active metals are found in the
s subshell
Valence electrons of transition metals are found in the
s and d subshells
valence electrons of lanthanide and actinide series metals are found
s and f subshells
copper, nickel, silver, gold, palladium, and platinum
transition metals that are relatively nonreactive that makes them ideal for coins and jewelry
Transition metals conductibility
good conductors
Metals electron transfer abilities
Easily give up electrons
Nonmetals
Upper right of periodic table, brittle in solid state, little or no metallic luster, high IE, EA, and EN, small atomic radii and large ionic radii
Nonmetals electron transfer abilities
DO NOT easily give up electrons
conductibility of nonmetals.
they are poor conductors
Metalloids
stair-step group of elements, semimetals because they share some characteristics with both metals and nonmetals, physical properties vary widely and can be combinations of characteristics
As you move from left to right the amount of protons in a nucleus increases, this causes what
the electron cloud to bind together tighter and closer to teh nucleus because the electrons feel a great electrostatic pull
Effective Nuclear Charge
electrostatic attraction between he valence shell electrons and the nucleus
a measure of the net positive charge experienced by the outermost electrons
The pull of the positivity of the nucleus is mitigated by
the nonvalence electrons that reside closer to the nucleus
effective nuclear charge _____ from left to right (for elements in the same period) (figure 2.4 page 47)
INCREASES
as you move down on the periodic table: ___ happens
the principal quantum number increased by one each time – so the valence electrons are separated from the nucleus by a greater number of filled principal energy levels (aka inner shells) more and more each time
what does increased separation of the valence electrons and nucleus result in?
reduction in the electrostatic attraction between the positively charged nucleus and valence electrons, so the outermost electrons are held less tightly by the nucleus
z-eff is constant in a group, why?
as you go down a group the increased shielding (caused by the inner shells) cancels out the positivity of the nucleus