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...

to predict, a, the radius of the electron orbiting in the ground state of the hydrogen atom. This value is now called the Bohr radius.: 197  The first Solvay...

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...

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...

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

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...

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))...

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...

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...

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...

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...

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...

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...

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...

particle scattering occurs close to the centre of an atom, at a radius 10,000 times smaller than the atom. The electrons have negligible effect. He begins...

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

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...

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...

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...

observed—there is very little increase of the radius down the group due to the presence of poorly shielding f orbitals. The atoms in metals have a strong attractive...

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...

differential geometry, the radius of curvature, R, is the reciprocal of the curvature. For a curve, it equals the radius of the circular arc which best...

thereby avoiding the collisions with atoms that normally create electrical resistance. (Cooper pairs have a radius of roughly 100 nm, so they can overlap...

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,...

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)...

assuming all atoms are hydrogen atoms (which are about 74% of all atoms in the Milky Way by mass), the estimated total number of atoms in the observable...

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...

gaseous atom, positive ion, or molecule. The first ionization energy is quantitatively expressed as X(g) + energy ⟶ X+(g) + e− where X is any atom or molecule...