neptunium
Definition
Neptunium is a chemical element with the symbol Np and atomic number 93. It is a transuranic element, meaning that it has an atomic number greater than uranium. Neptunium is the first transuranic element to be discovered, in 1940. It was named after Neptune, the Roman god of the sea.
Neptunium is a silvery-white metal that is very radioactive. It is also very toxic. Neptunium is created by bombarding uranium-238 with neutrons. Neptunium-237 is the most stable isotope of neptunium. It has a half-life of 2.14 million years.
Neptunium is used in nuclear reactors and in some types of nuclear weapons. It is also used in research into nuclear fusion.
Neptunium is a dangerous element, but it can also be used for good. It is important to use neptunium responsibly and to dispose of it safely.
How can the word be used?
Neptunium is a radioactive element that is not found in nature. It is created artificially in nuclear reactors.
Different forms of the word
Noun: A radioactive chemical element with the symbol Np and atomic number 93.
Adjective: Relating to neptunium.
Etymology
The word "neptunium" comes from the Latin word "Neptunus," which is the god of the sea in Roman mythology.
The word "neptunium" was first used in 1940 by Edwin McMillan and Philip Abelson, who discovered the element. They named it after Neptune, the Roman god of the sea, because it was the ninth transuranic element to be discovered, and Neptune is the ninth planet in the solar system.
Question
What does neptunium look like?
AQA Science Exam Question and Answer
Question:
Describe the discovery and significance of neptunium in the context of the periodic table. Explain its radioactivity and its role as a transuranic element.
Answer:
Neptunium, a synthetic chemical element, was first synthesized by Edwin McMillan and Philip H. Abelson in 1940. It was the first transuranic element to be produced artificially, marking a significant milestone in the expansion of the periodic table beyond naturally occurring elements. Neptunium's discovery paved the way for further research into transuranic elements and their properties.
Neptunium is highly radioactive, and its isotopes exhibit various decay modes, including alpha and beta decay. This radioactivity stems from its atomic structure, which is inherently unstable due to the imbalance between protons and neutrons in its nucleus. As a result, neptunium isotopes undergo radioactive decay to achieve a more stable configuration.
Being a transuranic element means that neptunium has an atomic number greater than that of uranium (atomic number 92). It doesn't occur naturally in significant quantities on Earth and is mostly produced through nuclear reactions in reactors or particle accelerators.
Neptunium's study is essential for understanding the behaviour of heavy elements and their nuclear properties. It has applications in nuclear reactors and is of interest in nuclear waste management due to its long-lived isotopes and potential for transmutation.