CG3+Evolution+of+the+Periodic+Table

Answer the questions, in complete sentences based on the article from Scientific American "The Evolution of the Periodic System".

1.) For each scientist listed, describe the contribution to the development of the periodic table. Antoine Lavoisier - french chemist, devised a list oh the 33 elements known at the time 1787

Johann Dobereiner - found out that of the known elements could be arranges by their similarities into groups of 3 which he called triads.

Peter Kremers - 19th century suggested that certain elements could belong to triads placed perpendicularly broke a new ground in comparing elements in two directions a feature that later proved to be an essential aspect of Mendeleev's system.

Jean-Baptist-Andre Dumas - focused on devising a set of math mathematical equations that could account for the increase of atomic weight amount several groups of chemical similarity elements

Alexandre Emile Beguyer de Chancourtois - french geologist whose system relied on fairly intricate geometric configuration: he positioned the elements according to increasing atomic weight along a spiral inscribed on the surface of a cylinder 45 degrees from the base

John Newlands - suggested that when elements were arranged in order of atomic weight any one of the elements show a property similar to those of the elements eight places ahead and eight places behind in the list a feature that Newland called the law of octaves

Julius Meyer - produced a periodic table that turned out to be remarkably similar to Mendeleevs famous version although Meyer failed to classify all the elements correctly

Henry Mosely - began by photographing the x-ray spectrum of 12 elements 10 of which occupy consecutive places in the periodic table he discovered that the frequency of the features called k lines in the spectrum of each element where directly proportional to the squares of the integers representing the position of each successive element in the table.

2.) What properties did Mendeleev use to arrange his periodic table? he used the properties of the atomic weight which were increasing and consisted of 63 known elements.

3.) What were some of the problems with Mendeleev's table? What discoveries support Mendeleev's Table? he had left spaces at first but had already come up with the atomic weights for them. the discovery's that support the table would be finding the weights and also how other scientist had found out that he had included in the periodic table.

4.) On which properties is the modern periodic table arranged? the properties used are the atomic number as a fundamental ordering principal for the periodic table instead of using atomic weight.

5.) Why is it called the __Periodic__ Table of the Elements? its called the periodic table because "periodic" reflects on the fact that the elements show patterns in their chemical properties in certain regular intervals.

Nice Job! Ms. H