Periods Flashcards
Dimitri Mendeleev and lathar Meyer
Triads
Triads
3 similar elements Atomic weight equal average of the atomic weights of the other two Chlorine bromine iodine Calcium strontium barium Sulfur selenium tellurium
First classification according to
Atomic weight
Law of octaves
English chemist JAR
Increasing of atomic weight with similar properties after each 7 elements
Newlands
Fist to detect a periodic pattern
Participated developments of the periodic table
Law of octave
Mendeleev
Predicted the discovery of germanium (eka-silicon) between zinc and arsenic similar to silicon
Modern periodic table
1913
Henry Moseley
Wavelength of X Ray spectral lines of number of elements
Ordered of X Ray emissions (atomic number)
Discovery of isotopes
No to atomic weight
Increasing of atomic number
Periodic trends
Sizes of atoms and ions Ionization energy Electron affinity Electronegativity Metallic character
Effective nuclear charge
Atom and electron attracted to the nucleus and repelled by the other electrons
Two factors that depends the nuclear charge
Zeff=Z-S
Z atomic number
S screen constant close to the number of inner electrons
Size of atom
Bonding atomic radius
Radius: one half of the distance between covalent oh bonded nuclei
Ionic size depends
Nuclear charge
Number of electrons
Orbitals in which electrons reside
Cations are smaller than their parent atoms
Outermost electron is removed and repulsions are reduced
Anions are larger than their parent atoms
Electrons are added ad repulsions are increased
Ions increase in size as you go down a column
Due to the increasing value of n
Isle letting series
Ions have the same number of electrons
Ionic size decreases with
An increasing nuclear charge
Ionization energy
Amour of energy required to remove an electron from the ground state of a gaseous atom or ion
It requires more energy to remove each successive electron
When all valence electrons have been removed
The ionization energy takes a quantum leap
Electron affinity
The energy change that occurs when an electron is added to a gaseous atom or ion
Electro negativity
Attract electrons to itself
Metal or nonmetal
cation or anion
Metal cation
Nonmetal anion
N
Atómica mass
