A Powerpoint made for my school on Döbereiner and Newland’s classification of elements describing and explaining the different patterns and structures in which the Elements were arranged before we encountered the Periodic Table of Elements as we know them today.
Also a Fun Fact:
The 4 newest elements on the periodic table have just been named:
-Nihonium and symbol Nh, for the element with Z =113,
-Moscovium with the symbol Mc, for the element with Z = 115,
-Tennessine with the symbol Ts, for the element with Z = 117,
-Oganesson with the symbol Og, for the element with Z = 118.
Döbereiner and Newland’s classification of elements
1. Döbereiner & Newland’s Classification of Elements
Afrah Aamer | Delhi Public School | X-B
2. Johann Wolfgang
Döbereiner
In work beginning in 1829,
Döbereiner discovered trends in
certain properties of selected groups
of elements. For example, the
average atomic mass of lithium and
potassium. Moreover, the densities
for some of these triads followed a
similar pattern. These sets of
elements became known as
"Dobereiner's Triads".
3. Döbereiner Triads
In 1817, Johann Wolfgang Döbereiner began to formulate one of the earliest
attempts to classify the elements. In 1829, he found that he could form some of the
elements into groups of three, with the members of each group having related
properties. He termed these groups triads. Some of the triads that were classified
by Döbereiner are:
• Chlorine, Bromine, & Iodine
• Calcium, Strontium, & Barium
• Nitrogen, Phosphorus, &Arsenic
• Lithium, Sodium, & Potassium
In all of the triads, the atomic weight of the middle element was almost exactly the
average of the atomic weights of the other two elements.
Cl Ca N Li
Br Sr P Na
I Ba As K
4. John Alexander
Reina Newlands
Newlands was the first person to
devise a periodic table of elements
arranged in order of their relative
atomic weights. Continuing Johann
Wolfgang Dobereiner's work with
triads and Jean-Baptiste Dumas'
families of similar elements, he
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."
5. Newlands’ Law of Octaves
If the chemical elements are arranged according to increasing atomic weight, those
with similar physical and chemical properties occur after each interval of seven
elements. Newlands was one of the first to detect a periodic pattern in the
properties of the elements and anticipated later developments of the periodic law.
sa
(do)
re
(re)
ga
(mi)
ma
(fa)
pa
(so)
da
(la)
ni
(ti)
H Li Be B C N O
F Na Mg Al Si P S
Cl K Ca Cr Ti Mn Fe
Co & Ni Cu Zn Y In As Se
Br Rb Sr Ce & La Zr -- --
