The Periodic Table and Periodic Law
Classifying the Periodic Table
6.1 Development of the Modern Periodic Table
The History of the Periodic Table
1870s
new scientific data with their discovery
1790s
Laviosier
list of 23 elements
Important People In Chemistry
John Newlands
1864 - Law of Octaves
Meyer and Mendeleev
1869 - both scientists made a connection between atomic mass and elemental properties
Mendeleev published first and therefore got the credit for the discovery
built his table by atomic mass
left blanks for underdiscovered elements
Moseley's Fix
1913 - changed the periodic table to current arrangement, ordered by atomic number
Periodic Law - statement that there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic weight
70 elements
6.3 Periodic Trends
Types of Elements
atomic radius - half the distance between nuclei of identical atoms that are bonded together
valence electrons - the outermost layer of electrons in an atom
ions - an atom or group of bonded atoms that has a positive or negative charge
cation - a positively charged ion (loses 1+ electrons)
anion - a negatively charged ion (gains 1+ electrons)
ionization energy - the energy required to remove an electron from an atom
electron affinity - the energy change that occurs when a neutral atom gains an electron
electronegativity - the ability of an atom to attract shared electrons when the atom is part of a compound
Metals
Metalloids
Nonmetals
solid at room temperature
Mercury (Hg) is the only liquid
luster
malleable
ductile
conductors of electricity and heat
States of Matter
some solid
1 liquid
mostly gases
dull, brittle solids
not malleable, ductile, or good conductors
share characteristics of metals and nonmetals
semi-conductors - will conduct electricity under certain conditions
Categorizing Elements
groups/families - vertical rows
periods - horizontal rows
Alkali Metals - group 1, except for hydrogen, extremely reactive
Alkaline Earth Metals - group 2
Transition Metals - groups 3-12
Inner Transition Metals - below the rest of the table, would be wedged between the Transition Metals and Alkaline Earth Metals
Lanthanide - part of period 6, below the table
Actinide Series - part of period 7, below the table
Boron Group - group 13
Carbon Group - group 14
Nitrogen Group - group 15
Chalcogens (Oxygen Group) - group 16
Halogens - group 17
Noble Gases - group 18