Sentences with phrase «atoms by electron»

Not exact matches

I've never seen inside an atom but I believe it has a dense nucleus and is surrounded by electrons in multiple energy levels.

Scientists buoy our longing for clarity by enumerating laws and speaking of atoms and electrons, but, laments Camus even they are reduced to using the «poetry» of planetary systems, i.e., they Can not rationally seize the reality they study.

Thus, at the lowest level, electrons tend to unite and converge in the atom; atoms converge by molecularization, crystallization; molecules unite by polymerization; cells unite by conjugation, reproduction, association; nerve ganglions concentrate and localize to form a brain by what might be called a process of cephalization; the higher animal groups form colonies, hives, herds, societies, etc.; man socializes and forms civilizations as foci of attraction and organization.

Let us think of an electron microscope giving the situation of a target T with an atom A in the target with an electron coming in and being scattered by the atom.

In my view this arises from the striving of partly completed atoms and molecules to complete their forms by capturing electrons.

«The action of one compound «atom» on another is not, by the scientific evidence, an aggregate action of the electrons and protons individually on each other.

As one moves up levels of organization — electrons, atoms, molecules, cells, and so on — the properties of each larger whole are given, not merely by the units of which it is composed, but by the new relations among these units.

We will be concerned, however, with mental models of systems which for various reasons can not be represented by replicas, such as the economy of a nation, the electrons in an atom or the biblical God.

It is by virtue of their physical properties that electrons and other particles combine in different ways to produce atoms, and so it is with atoms that find themselves in juxtaposition and then combine to produce molecules.

We (and science in general) start by accepting the real existence of certain scientific objects — atoms, electrons, gravitation, light, etc..

There are basically two types of lines, those produced by collisions between the atoms or ions and the electrons in the surrounding gas, which are called collision lines, and which are very bright for elements such as oxygen, nitrogen and neon, and lines which are produced when ions capture free electrons, which are called recombination lines, and which are bright only for those gases with the highest abundances in the interstellar medium: hydrogen and helium.

As its sharp - tipped probe scans a surface, the extent to which electrons «tunnel» between the tip and surface indicates changes in height caused by the presence of atoms.

All light comes from the same physical process: An electron circling the nucleus of an atom in its customary orbit is energized — often by heat — and moves into a higher orbit.

The atomic size and structure of nitrogen make it an excellent choice for this purpose because it can fit naturally into a strong network of carbon atoms by creating bonds (sp2) in which electrons are shared by the whole network.

To date, they all work by exciting electrons that are either floating freely or in atoms, prompting the emission of a burst of light.

This region is made up of hydrogen plasma, a gas of atoms whose electrons have been stripped away by the ferocious temperature, leaving just protons behind.

For the first time, they managed to control the shape of the laser pulse to keep an electron both free and bound to its nucleus, and were at the same time able to regulate the electronic structure of this atom dressed by the laser.

It is not currently feasible to engineer a material atom by atom, let alone control the quadrupolar behavior of electrons.

Between 150 and 350 kilometers above Earth's surface, the density of free - floating electrons should drop by a factor of two as they rejoin atoms, the researchers say.

Most significant was the September unveiling by Japanese researchers of a powerful linkage between two silicon atoms that share three pairs of electrons — a so - called triple bond.

«This gives us the option of creating new atoms dressed by the field of the laser, with new electron energy levels,» explains Jean - Pierre Wolf.

Ion engines work by stripping electrons from the atoms of an inert gas such as xenon, making them positively charged.

11 Now we sort elements by their number of protons, or «atomic number,» which determines an atom's configuration of oppositely charged electrons and hence its chemical properties.

«By applying an intensity of 100 trillion watts per cm2, we were able to go beyond the Death Valley threshold and trap the electron near its parent atom in a cycle of regular oscillations within the electric field of the laser,» Jean - Pierre Wolf says enthusiastically.

They also provide an avenue for designing other types of electron emitters with atom - by - atom precision, said Nick Melosh, an associate professor at SLAC and Stanford who led the study.

In particular, if an atom inside a solid such as a silica wafer is hit by an X-ray photon and a hole forms, it's not clear that the excited electron hangs around to form an exciton.

In certain isotopes of particular elements — species of atoms characterized by a given number of protons and neutrons — two beta decays can occur simultaneously, emitting two electrons and two antineutrinos.

This dual state would make it possible to control the motion of the electrons exposed to the electric field of both the nucleus and the laser, and would let the physicists to create atoms with «new,» tunable by light, electronic structure.

The more microwave radiation is absorbed by a resonator, the more likely it is to find an electron on the corresponding atom.»

Positronium atoms are like hydrogen atoms, except the proton is replaced by a positron, the positively charged antiparticle of the electron.

A chemical bond is the physical phenomenon of chemical substances being held together by attraction of atoms to each other through sharing, as well as exchanging, of electrons - or electrostatic forces.

In the late 1990s, Arthur Nozik of the National Renewable Energy Laboratory in Golden, Colorado, and the University of Colorado, Boulder, theorized that if the semiconductors were made out of nanoparticles, they could excite multiple electrons with less photon energy, because less of the incoming energy would be sapped by vibrating atoms in the crystalline lattice.

For the last 100 years, they have done that mostly by making and breaking the strong covalent bonds that form when atoms share electrons.

Electrons within atoms absorb light of a specific wavelength by jumping from one energy level to a higher one.

To make their engine, the researchers first enclosed the ion (a calcium atom with one electron removed) inside an 8 - millimeter - long funnel - shaped electrical trap created by four electrodes.

Li's team showed that during CRAND, cosmic rays entering Earth's atmosphere collide with neutral atoms, creating a splash that produces charged particles, including electrons, that become trapped by Earth's magnetic field.

Researchers in Spain have discovered that if lead atoms are intercalated on a graphene sheet, a powerful magnetic field is generated by the interaction of the electrons» spin with their orbital movement.

Atoms of most elements, such as hydrogen, oxygen and carbon, form tight chemical bonds by sharing electrons with their neighbours in order to give each atom a stable configuration of electrons.

It consists of electron transfer to the originally ionized Ne atom matched by energy transfer away from the Ne, which leads to ionization of the second Kr atom nearby.

The atom is a helium nucleus orbited by an electron and an antiproton rather than two electrons.

It's the result of a particular magnetic property of materials — the magnetic moment, a tiny magnetic field produced by electrons orbiting the nucleus of an atom.

Electrons occupy different orbits around their atom and, by analogy, spin like Earth.

The collective flipping of large numbers of metallic nanowire atoms, forced by a large number of electrons in the electric current, moves the domain wall — and the data bits it separates — along.

In space, the cosmic microwave background was scattered by atoms and electrons and became polarized too.

«This is similar to x-ray diffraction, but by using electrons we get a much larger signal, and the high energy of the probe electrons gives us better access to measuring the precise motion of atoms,» Zhu said.

The engine creates thrust by accelerating xenon ions — atoms stripped of one or more electrons, giving them a positive charge — through the negatively charged grid and spewing them out the back of the ship at 4,000 miles per hour.

An «NV -» center can be created within a diamond's scaffold - like structure by replacing a missing carbon atom with a nitrogen atom (N) that has trapped an electron making the center negatively charged.

Motivated by evidence that electrons in groups of aluminum atoms might form closed «shells,» physicists A. Welford Castleman Jr. at Pennsylvania State University and Shiv N. Khanna at Virginia Commonwealth University began searching for stable configurations of these atoms.

To achieve this the researchers took advantage of the manner in which Fe atoms move across the surface of graphene when irradiated by electrons in a transmission electron microscope (TEM).

One of the most ubiquitous is the «octet rule,» which states that each atom in a molecule that is produced by a chemical reaction will have eight outer orbiting electrons.