This is known as the electrostatic, or Coulomb, force. If the two nuclei are headed for a collision, they must overcome a strong repulsive force that opposes their fusion into a new element. "If you think of an atom being the size of the Melbourne Cricket Ground (approximately 170 metres in diameter), the nucleus is a small grape at the centre of that," she says. To create a new element, the nuclei from each atom must collide and fuse. The nucleus takes up only a tiny fraction of the space an atom occupies. While a sheet of foil might look solid to the human eye, it's much different on the atomic scale. If this happens, there is a chance that they will fuse together to form a heavier element." "If the accelerated atom is going fast enough, it is possible that its nucleus - the compact core of protons and neutrons at its centre - might make contact with the nucleus of one of the heavier atoms. "The way we typically create these elements is that we have a lighter atom, say calcium, and we accelerate that and smash it into a foil made up of heavier atoms," says Williams. In the last year alone, researchers have created atoms of two new elements: 117 - known as ununseptium for now - and 115 - ununpentium. Most of these have been made using a particle accelerator. Since 1939, all newly discovered chemical elements have been synthesised in the laboratory. "But it is quite possible that some of the elements we have synthesised here on Earth may also be created out in the Universe, in more extreme environments than those we find here on Earth," says Williams. "Based on what we know about how to create heavy elements in a lab, this natural process would have to be pretty extreme, and also fairly common, for us to detect a new element in our environment." However, she says, synthesising super-heavy elements in the lab can help scientists better understand the properties of these elements and how they are created, which then helps them understand if and how any more naturally occurring elements may be found. "First, there would have to be a natural process that would produce these elements, and secondly the elements would have to live long enough (and in sufficient quantity) for us to detect their existence. She says two things are needed in order for new naturally occurring super-heavy elements to be discovered. The only elements left to discover fall into the super-heavy category - elements that contain more than 104 protons - says Dr Elizabeth Williams, a nuclear physicist at the Australian National University.īut it is unlikely we will discover any new naturally occurring super-heavy elements on Earth, says Williams. Since that discovery, plutonium (94), neptunium (93) and astatine (85), which were initially created in the lab in 1940, have since been found in nature. The last naturally occurring element to be discovered was francium (87) in 1939. More than three-quarters of the elements on the periodic table exist naturally on Earth or elsewhere in the Universe. Some of the elements are well-known, such as hydrogen (1), oxygen (8) and carbon (6), while are less so seaborgium (106), flerovium (114) and darmstadtium (110). The atomic number of an element is determined by how many protons are found in the nucleus of an atom of that element. The periodic table contains more than a hundred chemical elements, the basic building blocks of the everything around us - living and non-living.
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