Rutherfordium
Rutherfordium is a synthetic chemical element. Its official chemical symbol is Rf, and its atomic number is 104, which means that a rutherfordium atom has 104 protons in its nucleus. Rutherfordium was the first super-heavy element to be discovered. Super-heavy elements are located in period 7 – the bottom row of the periodic table of elements. The element is named after one of New Zealand’s most famous scientists – Lord Ernest Rutherford.
Period 7
Rutherfordium – element 104 – is the first of the super-heavy elements in period 7.
Synthetic elements explained
Synthetic elements do not occur naturally on Earth. There are 26 synthetic elements. There are also a few elements like astatine (At) that were first synthesised but later discovered as naturally occurring in trace amounts. In the case of astatine, there are about 25–28 g of it in the Earth’s crust – the same weight as a slice of bread! It’s easier to synthesise astatine rather than ‘find’ this unstable element.
Synthetic elements are produced in nuclear reactors, particle accelerators or atomic bombs. Rutherfordium is created by nuclear bombardment – smashing tiny bits of atoms into other atoms. This is fitting because Ernest Rutherford pioneered the research that first split an atom in 1917.
All of the synthetic elements are radioactive and unstable. They do not exist for long because of radioactive decay.
Elemental rutherfordium
On the periodic table of elements, rutherfordium is represented by the symbol Rf. It has an atomic number of 104 because it has 104 protons in its nucleus. It is a synthetic element because it is created in a laboratory rather than occurring naturally.
A controversial element
Element 104 has a controversial past, beginning with its discovery. In 1964, Russian scientists from a lab in Dubna were the first to synthesise the element. In 1969, American scientists used a different method to synthesise element 104 and discovered additional information about it. In 1973, an independent team confirmed the American synthesis .
The naming rights for a newly discovered element goes to the person or team who discovers it. The Russian team named element 104 kurchatovium (Ku) in honour of Igor Kurchatov, a famous Soviet nuclear physicist. The American team challenged the Russians’ discovery claim and named element 104 rutherfordium (Rf) in honour of Ernest Rutherford, often called the father of nuclear physics.
Disputes also arose over the names of elements 105 and 106. Scientists referred to this controversy as the Transfermium Wars because it involved the elements that followed fermium on the periodic table of elements.
The International Union of Pure and Applied Chemistry (IUPAC) is responsible for approving the names of elements. Until it could settle the dispute, it used the temporary name unnilquadium (Unq) – the Latin names for the numbers 1, 0 and 4. IUPAC eventually decided that the American and Dubna scientists should share the credit for the discovery. In 1997, IUPAC gave the name rutherfordium to element 104 and the name dubnium (Db) to element 105.
There is one naming convention that everyone has agreed on in recent times – all new elements end with the letters -ium.
New Zealand $100 note
Rutherford along with his Nobel Prize are featured on New Zealand’s $100 note. Overlaying the medal is a graph plotting the results from Lord Rutherford’s investigations into naturally occurring radioactivity. The background pattern, whakaaro kotahi, is from the wharenui Kaakati at Whakatū Marae in Nelson.
Note: The Reserve Bank of New Zealand Act 1989 restricts the reproduction of banknotes. Consents to the use of reproductions and images of New Zealand banknotes must adhere to the following guidelines.
A second naming controversy
A second controversy about names is probably only recognised by New Zealanders. Ernest Rutherford was born, raised and (mostly) educated in New Zealand, and we claim him as one of our greatest scientists. Rutherford’s amazing discoveries took place in labs in Canada and England so he is often referred to as either a Canadian scientist or British scientist – which New Zealanders strongly dispute!
Ernest Rutherford with Hans Geiger
Ernest Rutherford (on the right) with Hans Geiger at the University of Manchester. The Geiger-Marsden or ‘gold foil’ experiment was carried out by two students on instruction from Rutherford. From these results, Rutherford put forward the now accepted nuclear model of an atom with a central dense nucleus with electrons orbiting this nucleus.
An interesting (but not very useful) element
Ever since Dmitri Mendeleev first produced the periodic table of elements, scientists have been trying to fill in the gaps for proposed but undiscovered elements. The real value of an element like rutherfordium is in the knowledge it provides. Only a few atoms of this element have been synthesised. In its most stable form, rutherfordium only has a half-life of 1.3 hours, so it is difficult to study. The only thing we really know about it is that it is a solid at room temperature.
Nature of science
Scientists have spent over 50 years researching elements like rutherfordium – and not really coming up with much information about their usefulness outside of the lab. But that is one of the wonderful things about science. This type of scientific knowledge is valued because it helps scientists continue to piece together the puzzle of our natural world.
Related content
These articles provide background information about elements and how they are grouped:
Rutherfordium is named after the great Kiwi scientist Ernest Rutherford. Find out about other great New Zealand scientists:
