1. Sir William Crookes and His Contribution to Atomic Theory
By Brody Donaldson

2. Date of Birth
June 17th, 1832
The Institution of Engineering and Technology. "Sir William Crookes." N.p., n.d. Web. 1 Dec < y/archives/biographies/crookes.cfm>

3. The Chemical News is Founded
Sir William Crookes first published this magazine in the year 1859, he continued to publish it until 1906.
In this magazine he would later publish his new findings.
The Institution of Engineering and Technology. "Sir William Crookes." N.p., n.d. Web. 1 Dec < chives/biographies/crookes.cfm>.

4. Discovery of Thallium
In 1861 Crookes discovered this new element through spectroscopic methods.
Thallium was discovered accidentally while Crookes was looking for something else.
National High Magnetic Field Laboratory. "William Crookes." N.p., n.d. Web. 1 Dec < s/pioneers/crookes.html>.

5. Atomic Weight of Thallium
In 1873 Crookes made his final determination on the atomic weight of his newly discovered element.
Encyclopædia Britannica. "Sir William Crookes." N.p., n.d. Web. 2 Dec < /Sir-William-Crookes>

6. Characteristics of Cathode Rays
Crookes discovered new characteristics of cathode rays in the year He found that…
They travel in straight lines.
They cause glass to fluoresce.
They impart a negative charge to the objects they strike.
Electric and magnetic fields deflect them, suggesting a negative charge.
Buescher, Lee. "Atomic Structure Timeline." N.p., n.d. Web. 2 Dec <

7. Crookes Dark Space
Crookes also observed the dark space around cathode rays.
Encyclopædia Britannica. "Crookes Dark Space." N.p., n.d. Web. 2 Dec < opic/143949/Crookes-dark-space>.

8. A Spinthariscope is Developed
In 1903 Crookes developed this device, used for the study of alpha particles.
The spinthariscope allowed for the viewer to see matter decay.
Oak Ridge Associated Universities. "Crookes Spinthariscope." N.p., n.d. Web. 2 Dec < ookes.htm>.

9. Date of Death
April 4th, 1919
The Institution of Engineering and Technology. "Sir William Crookes." N.p., n.d. Web. 1 Dec < /library/archives/biographies/cro okes.cfm>