Its Symbol:

Neptunium’s symbol is “Np.”

Atomic Number:

Neptunium’s atomic number is 93.

Atomic Weight:

Its atomic weight is 237.


Neptunium’s color is silver.

Melting Point

Its melting point is 917 K (644°C or 1191°F).

Boiling Point

Its boiling point is 4175 K (3902°C or 7056°F).


It has 93 protons and electrons in its nucleus.


Neptunium has 144 neutrons in its nucleus.

Discovery of Neptunium:

Neptunium was discovered in 1940, by Edwin McMillan, and by Phillip H.     Abelson. Edwin McMillan was born on September 18, 1907. He was born in California. He is an American scientist who won the noble prize. Phillip H. Abelson was born on April 27, 1913. He is from Tacoma, United States. He got a Nation Medal of Science.

Its Atomic Configuration:

On the first shell it consists of 2 electrons, the second shell consists of 18 shells, the third consists of 18 electrons. The fourth shell has 32 electrons,  the fifth shell has 23 electrons. The sixth shell has 8 electrons and lastly the last one has 2 electrons.


It costs $660 per gram. 

How Long Does It Last:

It will last about a half of life, about 2 million years.

What is it used for:

Neptunium is used for making a device that detects neutrons. So if you put something in front of it, it will detect the neutrons inside of that object.