On February 18, 1930 he discovered Pluto at the Lowell Observatory in Flagstaff, Arizona.
Who is Clyde W. Tombaugh?
100
This is the lightest gas.
What is hydrogen?
100
Phoenix is the capital of the 48th State.
What is Arizona?
100
This is the longest river in South America.
What is the Amazon?
100
A typical adult human has this many bones.
What is 206?
200
He is known as "The Father of Modern Science."
Who is Galileo Galilei?
200
This element is never found free in nature, but is obtained by electrolysis of the chloride or hydroxide.
What is potassium?
200
On December 7, 1787 this colony became the first United State.
What is Delaware?
200
This is the longest river on Earth?
What is the Nile?
200
This is the largest bone in an adult human.
What is the femur?
300
He was a French chemist and microbiologist who was well known for his discoveries of the principles of vaccination, microbial fermentation and pasteurization
Who is Louis Pasteur?
300
The pure version of this element has the highest electrical and thermal conductivity of all metals.
What is silver?
300
On August 21, 1959 this island chain became the 50th state.
What is Hawaii?
300
This is the longest river in the Untied States?
What is the Mississippi?
300
The brain is generally divided into this many lobes.
What is four?
400
He is best known for his laws of planetary motion.
Who is Johannes Kepler?
400
The symbol for this element is W.
What is tungsten?
400
The postal abbreviation for this state is MO?
What is Missouri?
400
This river flows through London?
What is the Thames?
400
This fibrous tissue connects bone to bone.
What is a ligament?
500
He was a Serbian American inventor, electrical engineer, mechanical engineer, physicist, and futurist best known for his contributions to the design of the modern alternating current electricity supply system
Who is Nikola Tesla?
500
The symbol for this element is Na.
What is sodium?
500
The postal abbreviation for this state is IA?
What is Iowa?
500
This river flows through Paris.
What is the Seine?
500
This fibrous tissue generally connects muscle to bone.