Test 5- Periodicity Flashcards
Johann Wolfgang Dobereiner
- German chemist who is best known for work that foreshadowed the periodic for the chemical element
- Discovered trends in certain properties of select groups of elements
- Proposed the Law of Triads
John Alexander Reina Newlands
- The first person to devise a periodic table of elements arranged in order of their relative atomic weights
- Published in 1865 his law of octaves, which stated that any given element will exhibit analogous behavior to the eighth element following it in the table.
Lothar Meyer
- German scientist best known for his part in the periodic classification of the elements
- Organized 28 elements by atomic weight and valence electrons
- Came before Mendeleev- possibly sent to him
Dmitri Mendeleev
- Came to him in a dream
- Russian chemist proposed an organization scheme of all the know elements based on valence electrons and atomic weight
- Predicted the existence of 8 new elements and their masses
Henry Moseley
In 1911 he determined that each element had a unique atomic number using x-rays
Periodic Law
The Periodic Law states that the physical and chemical properties of the elements recur in a systematic and predictable way when the elements are arranged in order of increasing atomic number.
Characteristics of Metals
- Metals are malleable, ductile, can conduct heat and electricity, have a metallic luster, have a few valence electrons (1-3), exhibit metallic luster, can be representative, transitional, or inner transitional (rare earth)
- Valence electrons not attracted to nucleus instead of attaching to 1 atom, floats between all atoms, bonding them together, 1 VE not as strong (metallic bond), number of VE determines strength of metallic bond
Delocalized
float among all electrons and cause metallic bond
Malleable
can hammer into shape
Ductile
pulled in wires
Representative/Transitional/Intertransitional
- Representative metals- Always lose the same amount of electrons when they lose electrons, form ions that always have the same charge
- Transitional and inter transitional form ions with varying charges
Characteristics of nonmetals
- Opposite of metals
- not malleable
- not ductile
- doesn’t conduct heat and electricity
- many Valence electrons
Can determine the __ from the periodic table
electron configuration
Liquids on the periodic table
Bromine (not liquid) and Mercury
Gases on the periodic table
- 7 diatomic elements (Br, I, Cl, N, H, O, F) Br and I aren’t gases but they’re atomic
- Nobel gases.