Studied by 41 peopleatomic radii down a grp
increases
Electronegativity down a grp
Decreases
Ionization energy down a grp
Decreases
Electron Affinity down a grp
Decreases
Zeff down a grp
Constant
Shielding down a grp
increases
atomic radii across a period
decreases
Electronegativity across a period
increases
Ionization energy across a period
increases
Electron affinity across a period
increases
Zeff across a period
Increases
Shielding across a period
constant
What is Atomic Radius
The radius of an atom .... (how big)
What is electronegativity
the tendency of an atom to attract an electron towards itself
What is ionization energy
the amount of energy required to remove an electron from an atom
What is electron affinity
the change in energy (kj) when an electron is added (the atom's likeliness of gaining an electron)
Zeff
effective nuclear charge ( Zeff = Z-S .... z= # of protons .... s= # of core electrons)
Sheilding
a reduction in effective nuclear charge (zeff), due to energy levels blocking the valence electrons from feeling the charge of the nucleus
Johann Doberereiner
Lived from : 1780 - 1849
1829; Classified elements into grps of 3 .... triads.
Each triad had similar chemical properties and orderly physical properties (Chlorine, Bromine and Iodine)
John Newlands
Lived from 1838 -1898
1863; Suggested elements be arranged in "octaves"
He noticed that the properties repeat every 8 elements
(law of octaves)
Law of octaves failed past calcium
Ridiculed by chemical society XDDD (L Bozo)
Mendeleev
Lived 1834-1907
Created the first periodic table
Arranged elements according to atomic mass, similarities and chemical properties
1871; he predicted the properties of elements that would fill up gaps in his table ..... in 1886 the three elements he predicted were found 🤯
remember ms tujauge screaming MENDELEEV!!!!
Henry Moseley
Lived 1887 -1915
English Physicist who worked with Rutherford
Figured out the acc nuclear charge (atomic number) of elements
Periodic Law
States that when elements are arranged in order of increasing atomic number.... THERE IS A PATTERN !!!!
Glenn T. Seaborg (YEAAAAA)
1912-1999
Co-Discovered 10 new elements
1844; Moved 14 elements out of the main body of the periodic table and created the Actinide series (under the Lanthanides)
Had an element named after him while he was still alive
WHere are the metals
Generally to the left of the periodic table
Where are the metalloids
The diagonal line starting with Boron
WHere are the nonmetals
Generally to the right of the periodic table (+ hydrogen)
List the grp names left to right
Alkali metals
Alkaline earth metals
Transition Metals
Inner transition metals (Lanthanides top, and Actanides bottom)
Main grp elements
Halogens
Noble gases
What are the properties of metals
Good heat and electricity conductors
Usually solid at room temp
Malleable
Ductile
SHiny Luster
Mercury is the only liquid metal
What are the properties of nonmetals
Poor heat and electricity conductors
Can be solids, liquids or gases at room temp
Solids are usually brittle and dull
bromine is the only nonmetallic element in liquid state
What are the properties of metalloids
Have properties of metals and nonmetals
Mostly brittle solids
Intermediate conductors of electricity - AKA emiconductors
Properties of alkali metals
Extemely reactive (water, or air) silvery appearance soft lower density low melting points not found freely in nature
properties of alkaline earth metals
harder and stronger that alkali metals high density, melting point than alkali metals less reactive than alkali not found freely in nature
Properties of halogens
Most reacitve nonmetals react with most metals to form salts most electronegative
properties of noble gases
least reactive because valence shell is compeltely filled
properties of transition metals (d block)
high density high melting point good conductor of heat and electricity high luster less reactive than the alkali or alkaline metals Birght colors
Properties of p block metals
Harder and more dense than s block softer and less dense than d block
Note
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