The Periodic Table And the Periodic Law
http://www.youtube.com/watch?v=zGM-wSKFBpo • http://www.youtube.com/watch?v=AGZ20OrmYBs • http://www.youtube.com/watch?v=xbf0HdLwLZA • http://www.youtube.com/watch?v=KYSAo9e_H9k
Chapter 6: The Periodic Table and Periodic Law • Section 6.1 Development of the Modern Periodic Table Antoine Lavoisier (1743-1794) • Composed a list in 1790 of the 23 elements known at the time.
The advent of electricity (used to break down compounds into their component elements- electrolysis) and the development of the spectrometer, used to identify elements lead to the discovery of many new elements (70 total by 1870)
Nuclear Magnetic Resonance (NMR) spectrometer
John Newlands • Noticed that when elements were arranged by increasing atomic mass their properties repeated every eight element.
John Newlands • This type of pattern is called periodic because it repeats in a specific manner. • Newlands called this relationship the Law of Octaves.
Dmitri Ivanovich Mendeleev(1834-1907) • Organized elements increasing atomic mass • Noticed that there was a repetition or periodic pattern in their properties.
Dmitri Mendeleev • Elements with similar properties were arranged in columns- this was the first periodic table
Dmitri Mendeleev • Mendelev predicted the existence and properties of undiscovered elements and left spaces where they should go.
Henry Moseley • Arranging the elements by mass resulted in several elements being placed in groups of elements with different properties.
Henry Moseley(1887-1915) • Discovered that atoms of each element contained a unique number of protons in their nuclei, the number of protons being equal to the atom’s atomic number.
Henry Moseley • By arranging elements by increasing atomic number, the problems with the order of the elements in the periodic table were solved.
The Periodic Law When elements are arranged by increasing atomic number, there is a periodic repetition of their chemical and physical properties.
The Modern Periodic Table • Consists of boxes that contain the elements name, symbol, atomic number and atomic mass.
The Modern Periodic TableGroups • The boxes are arranged in order of increasing atomic number in a series of columns called groupsor families.
The Modern Periodic TableGroups • Each group is numbered 1 through 18.
The Modern Periodic TableGroups • Each group is numbered 1 through 8, followed by the letter A or B.
Periods • The boxes are arranged in order of increasing atomic number in a series of rows called periods. • Beginning with hydrogen in period 1, there are 7 periods.
Main Group Elements • Groups 1,2,and 13-18 are referred to as the main group (or representative) elements because they possess a wide range of chemical and physical properties.
Transition elements • Transition elements • Groups 3-12
Classifying the Elements • Metals • All elements to the left side (except H) of the stair-step line from B to At
Metals • good conductor of heat and electricity • shiny luster • solid at room temperature (except Hg) • Malleable and ductile • high boiling and melting points • High densities
Metals (continued) • large atomic radius • low ionization energy • low electronegativity
Alkali Metals • The group 1 elements (except for H) • Most reactive group of metals !!!
Alkaline Earth Metals • The group 2 elements • Second most reactive group of metals
Transition Elements • These are the group B elements (all are metals)
Transition Metals • Transition Metals • Also known as the d-block elements
Inner transition Metals • Located along the bottom of the periodic table • Known as the lanthanide- actinide series • Lanthanides are also called rare earth elements • Many are radioactive • Also know as the f- block elements
Non- Metals • Occupy the upper right side of the periodic table • (right of the stair-step line from B to At)
Non-Metals (Characteristics) • Generally gasses at room temperature • Poor conductors of heat and electricity • Brittle dull-looking when solids • lower boiling and melting points than metals (except carbon) • usually have lower densities than metals
Non-Metals ( Other Characteristics) • high electronegativity • Small atomic radius • higher ionization energy than metals
Halogens • Group 17 elements • Most highly reactive group of the non-metals • Diatomic (Mr. BrINClHOF)
Nobel gases • Group 18 elements • Extreamly unreactive • also called Inert gases
Metalloids • Elements border the stair-step line from B to At • Physical and chemical properties of both metals and non-metals
Section review 6.1 • Laviosier,- Composed a list in 1790 of the 23 knownelements. Newlands: Noticed that when elements were arranged by increasing atomic mass their properties repeated every eight element Law of Octaves. Mendeleev : Organized elements increasing atomic mass Elements with similar properties were arranged in columns- this was the first periodic table predicted the existence and properties of undiscovered elements and left spaces where they should go Moseley:By arranging elements by increasing atomic number, the problems with the order of the elements in the periodic table were solved.