If we take the simple molecular orbital description of the ground state and combine that function with the functions describing all possible excited states using unoccupied orbitals arising from the same set of atomic orbitals, we also reach the full configuration interaction wavefunction.

If light ( photons ) of frequency ν < sub > 12 </ sub > pass through the group of atoms, there is a possibility of the light being absorbed by atoms which are in the ground state, which will cause them to be excited to the higher energy state.

If a collection of atoms are in the excited state, spontaneous decay events to the ground state will occur at a rate proportional to N < sub > 2 </ sub >, the number of atoms in the excited state.

If an atom is already in the excited state, it may be perturbed by the passage of a photon that has a frequency ν < sub > 21 </ sub > corresponding to the energy gap ΔE of the excited state to ground state transition.

If the ground state has a higher population than the excited state ( N < sub > 1 </ sub > > N < sub > 2 </ sub >), the process of absorption dominates and there is a net attenuation of photons.

If the lifetime of this transition, τ < sub > 21 </ sub > is much longer than the lifetime of the radiationless 3 → 2 transition τ < sub > 32 </ sub > ( if τ < sub > 21 </ sub > ≫ τ < sub > 32 </ sub >, known as a favourable lifetime ratio ), the population of the E < sub > 3 </ sub > will be essentially zero ( N < sub > 3 </ sub > ≈ 0 ) and a population of excited state atoms will accumulate in level 2 ( N < sub > 2 </ sub > > 0 ).

If a light source (' the atom ') is in the excited state with energy, it may spontaneously decay to a lower lying level ( e. g., the ground state ) with energy, releasing the difference in energy between the two states as a photon.

If the number of light sources in the excited state is given by, the rate at which decays is:

If the atom is in the excited state, it may decay into the lower state by the process of spontaneous emission, releasing the difference in energies between the two states as a photon.

If the positronium is created in such an excited state then it will quickly cascade down to the ground state where annihilation will occur more quickly.

If it is at a higher energy level, it is said to be excited, or any electrons that have higher energy than the ground state are excited.

* If an electron is excited into a higher state it leaves a hole in its old state.

" If we had a success, everybody — and I mean every cutter, every painter, every plasterer — was excited about it, was abuzz, was in a tizzy about the whole idea of picture making.

If the atom, which is now in the excited state, emits a photon spontaneously, it will be kicked by the same amount of momentum but in a random direction.

* If necessary, a state of ionization or an excited state may be indicated in the right superscript position ( e. g., state of ionization Ca < sup > 2 +</ sup >).

The scandal beat might not be her favorite, but Rodriguez understands that it's often what her audience gets excited about: " If I were to program a show for my viewing pleasure, I would make it all news ", said Rodriguez.

If the molecule absorbs light whose energy is larger than this gap, an electron in the HOMO may be excited to the LUMO.

If the bird is excited, it may repeat this call several times.

* If a cell is quiescent, then it remains quiescent unless one or more of its neighbours is excited.

* If a cell is excited, it becomes refractory at the next iteration.

If a material has a direct bandgap in the range of visible light, the light shining on it is absorbed, causing electrons to become excited to a higher energy state.

If an atom bomb in 1945 could destroy an entire city surely the atomic arsenal we now have is more than adequate to fulfill any military objective required of it.

`` If you substitute ' atom ' for ' angel ', the problem is not insoluble, given the metallic content of the pin in question ''.

If the joining of monomers takes place at such a carbon atom, the free hydroxy group of the pyranose or furanose form is exchanged with an OH-side-chain of another sugar, yielding a full acetal.

If there is still a tie, each atom in each of the two lists is replaced with a sub-list of the other atoms bonded to it ( at distance 3 from the stereocenter ), the sub-lists are arranged in decreasing order of atomic number, and the entire structure is again compared atom by atom.

If an atom A is double-bonded to an atom B, A is treated as being singly bonded to two atoms: B and a ghost atom that has the same atomic number as B but is not attached to anything except A.

If the addition of a functional group takes place at the less substituted carbon atom of the double bond, then the electrophilic substitution with acids is not possible.

If a neighboring atom moves to occupy the vacant site, the vacancy moves in the opposite direction to the site which used to be occupied by the moving atom.

If one cube has an A atom at its center, the atom is on a site usually occupied by a B atom, and is thus an antisite defect.

The well-known historian of physics, C. P. Snow, says about him, " If Fermi had been born a few years earlier, one could well imagine him discovering Rutherford's atomic nucleus, and then developing Bohr's theory of the hydrogen atom.

If the photon energy is absorbed, some of the energy liberates the electron from the atom, and the rest contributes to the electron's kinetic energy as a free particle.

* Heavy atom methods ( multiple isomorphous replacement ) – If electron-dense metal atoms can be introduced into the crystal, direct methods or Patterson-space methods can be used to determine their location and to obtain initial phases.

If the ship as a result of capture and utilization of 4 hydrogen atoms is nor accelerated or slowed down, then the momentum lost during their capture is equal to the momentum gained from the release of the helium atom from the nozzle:

If the lost " recoil energy " is small compared with the energy linewidth of the nuclear transition, then the gamma ray energy still corresponds to the energy of the nuclear transition, and the gamma ray can be absorbed by a second atom of the same type as the first.

If the photon is of lower energy, but still has sufficient energy ( in general a few eV to a few keV, corresponding to visible light through soft X-rays ), it can eject an electron from its host atom entirely ( a process known as the photoelectric effect ), instead of undergoing Compton scattering.

... If you could stop every atom in its position and direction ... you could write the formula for all the future ".

If she, Pamela, were being held responsible for his crimes, then hers must be the final act of expiation.

I showed her the shower and tub, and she said, smiling, `` If you really don't mind, I think I'll get clean in the shower, then soak for a few minutes in your tub.

If internal responsibility suggests acceptance of the socialist ideal of equality, then external responsibility implies adherence to principles of ideological supranationalism.

If Franklin was an authentic genius, then Alexander Hamilton, with his exceptional precocity, consuming energy, and high ambition, was a political prodigy.

If he is the child of nothingness, if he is the predestined victim of an age of atomic wars, then he will consult only his own organic needs and go beyond good and evil.

If it is an honest feeling, then why should she not yield to it??

If love reflects the nature of man, as Ortega Y Gasset believes, if the person in love betrays decisively what he is by his behavior in love, then the writers of the beat generation are creating a new literary genre.

If a child watched its progress he whispered, `` Hay, hay, load of hay -- make a wish and turn away '', and then stared rigidly in the opposite direction until the sound of the horses' feet returned no more.

If in any one calculation Ptolemy had had to invoke 83 epicycles all at once, while Copernicus never required more than one third this number, then ( in the sense obvious to Margenau ) Ptolemaic astronomy would be simpler than Copernican.

If to be innocent is to be helpless, then I had been -- as are we all -- helpless at the start.

Defoe then commented, `` If they Could Draw that young Gentleman into Their Measures They would show themselves quickly, for they are not asham'd to Say They want only a head to Make a beginning ''.

If the historian was convinced of his own correctness, then he should not allow his vision to become fogged by disturbing facts.

If man is actually the product of his environment and if science can discover the laws of human nature and the ways in which environment determines what people do, then someone -- a someone probably standing outside traditional systems of values -- can turn around and develop completely efficient means for controlling people.

If it will simply delay the debates until the qualifications are closed next spring, and then carry all the candidates on a tour of debates, it can provide a service to the state.

If they are to be commended for foresight in their planning, what then is the judgment of a town council that compounds this problem during the planning stage??

If the President of the United States really feels he won himself a `` lousy job '', then heaven help us all.

If we make it established custom that whenever butchery on the highways grows excessive, say beyond 25,000 per annum, then somebody is going to hang, it follows that the more eminent the victim, the more impressive the lesson.

If the raw population figures are crucially relevant, then it is idle to think of liberation, as idle as to suppose that Poland might liberate Russia.

If the UN troops are not mercenaries then the Hessians were not mercenaries either.

`` If they are here, then surely I have the right to be here '', Rousseau said.

If he failed to reach the riverbank in five minutes, say, then the skiffs would pull away and leave him groping in the mud.

If we had, then one of us would have had to go instead.

If our national interest lies in being able to fight and win a war rather than committing national suicide, then we must take a much more penetrating look at ballistic missiles.

If, for some reason such as economy, we are not going to develop aircraft nuclear propulsion with a sense of national urgency, then we should turn our effort to developing jet engines with a thrust-to-weight ratio of 12 or 15 to one.

If your pool is located on or near sloping ground, it may have natural drainage which is certainly more desirable than to be faced with the annual expense and labor of first pumping out the water and then scooping out all the debris.