Date post: | 07-Aug-2015 |
Category: |
Science |
Upload: | yahuvehs-ofgrace |
View: | 48 times |
Download: | 0 times |
PERIODIC TABLE
oShows all known elements in the universe.
oOrganizes the elements by chemical properties.
pte song.xspf
Hennig Brand First person to discover an element. In
1649, his experiments with distilled human urine resulted in the production of
a glowing white substance, which he named phosphorus.
J u l i u s Lo t h a r M e y e r
German chemist. He was one of the pioneers in developing the first periodic table of chemical elements. His book, Die modernen Theorien der Chemie, published in Breslau in 1862, contained an early version of the periodic table containing 28 elements, classified elements into six families by their valence.
DMITRI MENDELEEV
Russian Chemist and the first Scientist to make a periodic table similar to the one that is used today. He arranged the elements by atomic mass. On 1869, a formal presentation was made to the Russian Chemical Society, entitled “The Dependence Between the Properties of the Atomic Weights of the Elements”.
SCIENTIFIC BENEFITS OF MENDELEEV’S TABLE:1. It enabled Mendeleev to predict the discovery of new elements and left spaces for them. Ex. Silicon(Si)2. It provided for variance from atomic weight order.
In 1914, an English Physicist’s observation on
X-ray frequencies led to the development of modern Periodic law which states that the observation of
elements vary periodically with atomic number.
HENRY MOSELEY
What is the ATOMIC NUMBER?
o The number of protons found in the nucleus of an atom
Oro The number of
electrons surrounding the nucleus of an atom.
How do I find the number of protons, electrons, and neutrons in an element using the periodic table?
o # of PROTONS = ATOMIC NUMBER
o # of ELECTRONS = ATOMIC NUMBER
o # of NEUTRONS = ATOMIC NUMBER- ATOMIC WEIGHT
Helium (He)O Combined with
Oxygen to create a Nitrogen free atmosphere for deep sea divers to prevent Nitrogen necrosis