Nadlinger earned first prize in a national scientific photography competition run by the Engineering and Physical Sciences Research Council on February 12 for capturing this unusual image of a single lit atom. The picture is composed of about 8,000 individual images that were combined into one frame using computer software.
Atoms are the building blocks of everything around us and the only substance that is not made up of atoms (islands). In fact, there are many different types of atoms, such as hydrogen, oxygen, nitrogen, phosphorus, sulfur, and carbon. An element is a chemical compound that cannot be broken down into its components by chemical means; it is therefore considered to be absolute. For example, water is made up of two elements: hydrogen and oxygen. Each element has its own set of characteristics which can be used to identify it. Scientists use these properties to study elements inside samples from around the world.
Elements are classified according to how many electrons they have. If an element has an electronic configuration of [Xe] 2s2p3, then it is called a noble gas because they are very reactive and don't bond with other substances. Other elements have electronic configurations of [Kr] 3d4s, [Rb] 5s6p, [Sr] 4d5s, or [Ca] 4d10s.
Actual images of atoms aren't pictures at all. However, visible light has a wavelength of approximately half a micrometer (a two-millionth of a meter) and atoms are about one angstrom (a ten-billionth of a meter) wide. Visible light behaves erratically on the atomic scale, making it unsuitable for use in photography. Instead, physicists have used other types of radiation, such as electrons and neutrons, which do not behave randomly and so can be used to create accurate images.
Atomic photographs are usually made with electron microscopes or neutron microscopes. These instruments use beams of electrons or particles to build up a three-dimensional image of a sample. Atomic objects scatter electrons differently from their surroundings and so become visible. A similar effect is seen with neutrons: if they collide with other elements they are absorbed, and if not they escape and can be detected. Neutron microscopy is useful for observing chemical reactions inside samples because it does not damage many materials like x-rays do.
In 1934, American physicist Edwin McMillan built the first atomic microscope. It used high-energy electrons to produce an image of an atom's nucleus. This method is still used today by scanning electron microscopes (SEMs).
A neutron microscope uses beams of fast neutrons to generate an image. Because neutrons don't interact with most substances they can be used to view hidden details inside samples.
1955 Dr. Mueller subsequently recalled the 1955 microscope, saying, "It was a steamy day in August when I became the first person to view an atom." On that day, the regular array of atoms and crystal structure became plainly apparent through the field ion microscope I had created. The image showed many more atoms than could be found in a piece of sugar; it was even possible to see individual electrons.
Before this discovery, scientists believed that atoms were invisible objects composed of tiny particles called nuclides that interacted with each other. They knew from experience that some elements are made up of smaller pieces called isotopes which have different numbers of neutrons (unpaired protons). For example, carbon has six protons and six neutrons, so it is considered a stable element. However, certain isotopes of carbon are radioactive because they have an extra neutron which causes them to decay or break down into another element over time. This process occurs very quickly for carbon-12 which has six neutrons and therefore does not decay, but carbon-14 which has seven neutrons can decay into nitrogen-14 which has seven protons and zero neutrons. Scientists thought that atoms were just collections of neutrons and protons that could not be seen with traditional microscopy, but rather only by using magnetic lenses to focus radiation emitted by these elements.
An conventional camera can photograph the atom if there are enough excited electrons emitting enough light. However, this does not imply that you will be able to see the atom with your own eyes. This is a long-exposure photo, so even with all that laser light, it's still too dim to see without special equipment.
The short answer is no, you cannot take a single image of an atom. But what you can do is take a series of images at different times or under different conditions and use other measurements to understand how the atom has changed over time.
In fact, that's exactly what people do when they use electron microscopy to study atoms and molecules. They take many pictures of the same spot or set of spots on the sample object. The difference between each picture is the amount of energy the electron beam receives from the microscope lens system (which controls where on the sample the beam hits). At low energies, the beam will pass through the sample and exit out the back; at high energies, it will be blocked by the electrons in the sample. Between these two extremes lies a range of energies at which the electron beam interacts with the sample material - causing changes that can be seen under the microscope. By comparing several such images, it is possible to build up a complete picture of what the sample looked like at different times.
This type of experiment is useful for studying processes that happen very quickly, such as chemical reactions.
A high-powered laser strikes the strontium atom in the photo, causing the electrons circling the strontium atom to become more energetic. These charged electrons will occasionally emit light. But only a special camera can see atoms and molecules this way.
In 1955, American physicist Willis E. Lamb Jr. calculated what today's technology could reveal about the inner workings of atoms. He concluded that even with today's technology, we would never be able to see an atom's nucleus because too many electrons are involved. However, he did estimate that a visible image might be possible if electrons were ejected from the atom one at a time instead of in bunches.
Lamb's calculation was based on theoretical models of atoms at that time. Since then, scientists have improved computer modeling techniques and now have a much better understanding of how atoms work.
Today, most physicists agree that Lamb was right about not being able to see the nucleus with today's technology; however, some still argue over how many electrons must be ejected before they can be seen with ordinary eyes.