The atomic radius of a chemical element is a measure of the size of its atom, usually the mean or typical distance from the center of the nucleus to the...

emission spectra, along with predicting a fixed radius for each of these levels. In the simplest atom, hydrogen, a single electron orbits the nucleus...

der Waals radius, rw, of an atom is the radius of an imaginary hard sphere representing the distance of closest approach for another atom. It is named...

Bohr radius and r 0 {\displaystyle r_{0}} is the classical electron radius. If this were true, all atoms would instantly collapse, however atoms seem...

Ionic radius, rion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated...

in units of the Bohr radius. Assuming that each atom in a simple metal cluster occupies the same volume as in a solid, the radius of the cluster is given...

orbital radius is less than 1/200th the electron's orbital radius (due to the mass ratio), the muon can be considered as a part of the nucleus. The atom then...

smaller than the diameter of the atom itself (nucleus + electron cloud), by a factor of about 26,634 (uranium atomic radius is about 156 pm (156×10−12 m))...

physics, the Bohr model or Rutherford–Bohr model is an obsolete model of the atom, presented by Niels Bohr and Ernest Rutherford in 1913. It consists of a...

non-equivalent definitions of atomic radius. Depending on the definition, the term may apply only to isolated atoms, or also to atoms in condensed matter, covalently...

Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically...

long-held view is that the carbon atoms fit into octahedral interstices in a close-packed metal lattice when the metal atom radius is greater than approximately...

research team published a proton charge radius measurement via the Lamb shift in muonic hydrogen (an exotic atom made of a proton and a negatively charged...

that the radius of his gold central charge would need to be less (how much less could not be told) than 3.4 × 10−14 metres. This was in a gold atom known...

radius of fluorine is a measure of the size of a fluorine atom; it is approximated at about 60 picometres. Since fluorine is a relatively small atom with...

nucleus of an atom, about 1018 kg/m3; neutron stars also reach this density), such an accumulation would fall within its own Schwarzschild radius at about...

why Rydberg atoms have such peculiar properties: the radius of the orbit scales as n2 (the n = 137 state of hydrogen has an atomic radius ~1 μm) and the...

approximate radius of a helium atom, the smallest neutral atom 30.8568 pm – 1 rontoparsec 50 pm – radius of a hydrogen atom 50 pm – bohr radius: approximate...

The covalent radius, rcov, is a measure of the size of an atom that forms part of one covalent bond. It is usually measured either in picometres (pm)...

comparing the atomic radii of the atoms that form the bond to the length of bond itself. For example, the atomic radius of boron is estimated at 85 pm,...

determined by assuming that atoms are rigid spheres. The radius of the spheres is taken to be the maximum value such that the atoms do not overlap. For one-component...

the cation-anion radius ratio can be used to predict the crystal structure of an ionic compound based on the relative size of its atoms. It is defined as...

element. The atomic radius is the distance from the atomic nucleus to the outermost electron orbital in an atom. In general, the atomic radius decreases as we...

the atom. From his results for a head on collision, Rutherford knows that alpha particle scattering occurs close to the center of an atom, at a radius 10...

A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include...

ionic radii determines the cation-anion distance, while the cation-anion radius ratio r + / r − {\displaystyle r_{+}/r_{-}} (or r c / r a {\displaystyle...

The problem of defining a radius for the atomic nucleus has some similarity to that of defining a radius for the entire atom; neither has well defined...

empirical radius of hydrogen atom 28 pm — covalent radius of helium atom 31 pm — covalent radius of hydrogen atom 31 pm — calculated radius of helium atom ~50...

An ion (/ˈaɪ.ɒn, -ən/) is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this...

investigate nuclear structure, accelerators were commonly referred to as atom smashers in the 20th century. The term persists despite the fact that many...