This document provides information on several important scientists and their contributions to the development of the atomic theory and periodic table. It discusses the early works of Aristotle, Democritus, and alchemists. It then focuses on the discoveries of Lavoisier, Dalton, Thomson, Goldstein, Roentgen, Becquerel, Curie, Millikan, Rutherford, Moseley, and Chadwick which helped establish modern atomic theory. It also outlines the early periodic table arrangements of Dobereiner, Newlands, Meyer, and Mendeleev which led to the successful establishment of the periodic table.

1. Project in
Science

2. Submitted to:
Miss Shiela Hernandez
Submitted By:
Abad, Malvin
Benoza, Dominique Anne
Isoli, Khelly Nicole
Masilungan, Edgardo
Oliver, Maurice
Pisuena, John Louise
Ramos, Regine
Tan, Nicole Andrea

3. Aristotle
-Aristotle did not believe in the
atomic theory He thought that
all materials on Earth were not
made of atoms, but of the four
elements, Earth, Fire, Water,
and Air. He believed all
substances were made of
small amounts of these four
elements of matter.

4. Democritus
-
Democritus greatest contrib
ution to modern science was
arguably the atomic theory
he elucidated. According
to Democritus' atomic
theory, the universe and all
matter obey the following
principles: Everything is
composed of “atoms”, which

5. Alchemists
-Alchemists in general were
responsible for using and
passing on all the general
techniques of chemistry, from
solution, calcination ,distillation,
cohobating, coagulation et,
without which the chemists and
early chemists would have had
a much harder time in the 17th

6. Antoine Lavoisier
-Lavoisier is most noted for his
discovery of the role oxygen
plays in combustion. He
recognized and named oxygen
(1778) and hydrogen (1783)
and opposed the phlogiston
theory. Lavoisier helped
construct the metric system,
wrote the first extensive list of

7. John Dalton
-Dalton's atomic theory remains valid in
modern chemical thought. 1) All matter
is made of atoms. Atoms are indivisible
and indestructible. 3) Compounds are
formed by a combination of two or more
different kinds of atoms.
John Dalton FRS (6 September 1766 –
27 July 1844) was an English chemist,
physicist, and meteorologist. He is best
known for his pioneering work in the
development of modern atomic theory;
and his research into colour blindness,
sometimes referred to as Daltonism, in
his honour.

8. John Joseph
Thomson
-J.J. Thomson discovered the
electron by experimenting with
a Crookes, or cathode ray, tube.
He demonstrated that cathode
rays were negatively charged.
In addition, he also studied

9. Eugene Goldstein
-Goldstein contributed greatly to the
study of cathode rays. He discovered
protons with the experiments he did
with cathode rays which would knock
electrons of atoms and attract them to
a positively charged electrode
Eugen Goldstein, (born Sept. 5, 1850,
Gleiwitz, Prussia—died Dec. 25, 1930,
Berlin), German physicist known for his
work on electrical phenomena in gases
and on cathode rays; he is also credited
with discovering canal rays.

10. Wilhelm
Roentgen
- Wilhelm Conrad Roentgen (1845-1923)
Contribution: Received the first Noble
Prize in physics for his discovery of x-rays
in 1901. On November 8, 1895, at the
University of Wurzburg, Roentgen was
working in the lab when he noticed a
strange fluorescence coming from a
nearby table. The German physicist,
Wilhelm Conrad Röentgen was the first
person to systematically produce and
detect electromagnetic radiation in a

11. Henri Becquerel
-Antoine Henri Becquerel (15
December 1852 – 25 August
1908) was a French physicist,
Nobel laureate, and the first
person to discover evidence of
radioactivity. For work in this field
he, along with Marie Skłodowska-
Curie and Pierre Curie, received
the 1903 Nobel Prize in Physics.

12. Marie Curie
-Marie Curie is one of the most famous
scientists that ever lived. Her contributions
such as the discovery of Radium and other
key elements help us out every day,
especially when getting an x-ray. Manya,as
she was called, was born Maria Sklodowska
in Warsaw, Poland on November 7, 1867
Marie Sklodowska Curie (1867–1934) was
the first person ever to receive two Nobel
Prizes: the first in 1903 in physics, shared
with Pierre Curie (her husband) and Henri
Becquerel for the discovery of the
phenomenon of radioactivity, and the
second in 1911 in chemistry for the

13. Robert Millikan
-His oil drop experiment helped to
quantify the charge of an electron,
which contributed greatly to our
understanding of the structure of the
atom and atomic theory.
American physicist Robert Millikan,
recipient of the 1923 Nobel Prize in
physics, "for his work on the
elementary charge of electricity and on
the photoelectric effect." Born in
Morrison, Illinois, Robert Andrew
Millikan was the second son of the
Reverend Silas Franklin Millikan and

14. Ernest Rutherford
-British physicist Ernest Rutherford (middle),
recipient of the 1908 Nobel Prize in chemistry,
"for his investigations into the disintegration of
the elements, and the chemistry of radioactive
substances." his most important contribution
to science. A consummate experimentalist,
Rutherford (1871–1937) was responsible for a
remarkable series of discoveries in the fields of
radioactivity and nuclear physics. He
discovered alpha and beta rays, set forth the
laws of radioactive decay, and identified alpha
particles as helium nuclei.

15. Henry Moseley
-Henry Gwyn Jeffreys Moseley (23
November 1887 – 10 August 1915) was
an English physicist, whose contribution
to the science of physics was the
justification from physical laws of the
previous empirical and chemical concept
of the atomic number. This stemmed from
his development of Moseley's law in X-ray
spectra. Moseley created the first atomic
battery.

16. James Chadwick
-English physicist, Sir James
Chadwick, recipient of the
1935 Nobel Prize in physics,
"for the discovery of the
neutron."

17. Johann Dobereiner
-A German scientist called Johann Dobereiner
put forward his law of triads in 1817. Each of
Dobereiner's triads was a group of three
elements. The appearance and reactions of the
elements in a triad were similar to each other.

18. John Newlands
-Newlands' Periodic Table. An English
scientist called John Newlands put
forward his law of octaves in 1864. He
arranged all the elements known at the
time into a table in order of relative
atomic mass. When he did this, he
found that each element was similar to
the element eight places further on.

19. Lothar Meyer
-Julius Lothar Meyer. Julius
Lothar Meyer (19 August 1830
– 11 April 1895) was a
German chemist. He was one
of the pioneers in developing
the first periodic table of
chemical elements.

20. Mendeleev
-In 1869, just five years after John
Newlands put forward his Law of
Octaves, a Russian chemist called
Dmitri Mendeleev published a periodic
table. Mendeleev also arranged the
elements known at the time in order of
relative atomic mass, but he did some
other things that made his table much
more successful.