Slides in this set
How the Modern Periodic Table
· The modern Periodic Table is laid out in order of increasing proton
number (atomic number), also the reactivity and the properties.
· Elements are represented by chemical symbols
· Going down, vertically, is known as a group and the groups are
decided by the number of electrons in the outer shell.
· Going across, horizontally, is know as a period and the period
number relates to how many shell an atom has.
· Starting from the left side of the periodic table, the reactive metals,
then the transition metals, then the non-metals and finally the noble
· In group 1, the elements react more as you go down.
· In group 7, the elements react less as you go down.…read more
· He arranged the elements in order of their mass,
measured in various chemical reactions.
· In 1808 he published the table of elements in his book A
New System Of Chemical Philosophy.
· They didn't know about protons and electrons so there
was no such things as atomic mass.…read more
In 1862, a year before Newlands
idea, Alexandre had come up with
a good attempt at sorting out elements.
· He showed similarities between every 8
element in a clear table.
· However, when his work was published, the
diagram was not included.…read more
In 1863, developed Daltons theory with his
Law of Octaves.
· He based his idea on the observation that the properties
of every eighth element seemed similar.
· However, because he was determined to make his
theory work he made vital errors.
· He didn't leave any room for new elements even though
new ones were turning up all the time
· He also put two elements in the same place to make
· So other scientists didn't accept his ideas.…read more