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Love and addiction ATLANTA -- The reward mechanism involved in addiction appears to regulate lifelong social or pair bonds between monogamous mating animals, according to a Center for Behavioral Neuroscience (CBN) study of prairie voles published in the January 19 edition of the Journal of Comparative Neurology. V1aR receptors, which are thought to be activated in the male vole brain during pair bond formation, were confined largely to the ventral pallidum. OTR receptors, which play a crucial role in pair bond formation in females, were found mainly in the nucleus accumbens. www.sensualism.com /love/addiction.html   (470 words)

ChemViz Molecular Shapes and VSEPR Theory Lab It states that the geometry of a molecule is determined by the repulsion forces of its valence electron pairs. The bond angle is the angle formed by two pairs of valence electrons and the central atom that connects the two. The stronger the repulsion strength, the larger the bond angle. chemviz.ncsa.uiuc.edu /content/lab-s-shapes.html   (584 words)

Chemical bond - Wikipedia, the free encyclopedia A chemical bond is the physical phenomenon of chemical species being held together by attraction of atoms to each other through sharing, as well as exchanging, of electrons or photons and is a phenomenon that is fully described by the laws of quantum mechanics. Coordinate covalent bonding is a special type of bonding, in which the covalent bonding electrons originate solely from one of the atoms, but are approximately equally shared by both in a molecular type bonding orbital. The Banana bond is a kind of bonding in which the bond bends, often due to the presence of an influencing atom in the middle of another covalent bond. en.wikipedia.org /wiki/Chemical_bond   (2641 words)

Pair bond - Wikipedia, the free encyclopedia In biology, a pair bond is the strong affinity that develops in some species between the male and female in a breeding pair. Pair-bonding, from 1940, is a term frequently used in sociobiology and evolutionary psychology circles and is typically meant to imply either a life-long monogamous relationship or a stage of mating interaction in socially monogamous species. Pair bonding is also sometimes seen between individuals of the same sex, as demonstrated by behavior similar to that of male-female pair-bonded individuals. en.wikipedia.org /wiki/Pair-bonding   (369 words)

Bond (chemistry) - ninemsn Encarta When a bond is formed between atoms, energy is normally given out because the resulting compound is at a lower energy level, and therefore more stable, than the original atoms. The energy required to break a bond is called its bond energy (or bond enthalpy), and is a useful quantity when the stability of compounds is being studied. Covalent bonds are formed when atoms share electrons, one from each atom in a single bond, to form electron pairs, usually making their outermost shells up to eight electrons by this means. au.encarta.msn.com /encyclopedia_761563675/Bond_(chemistry).html   (1649 words)

Chemical bonding: covalent bond This paired sharing also allows the formulas of a large number of compounds to be rationalized and predicted— a fact that led to the widespread acceptance of the Lewis model by the early 1920s. Bond length measurements are entirely consistent with this interpretation; they are almost exactly halfway between the values found in compounds known to contain single and double bonds. The details of this bonding arrangement are discussed in the section on the hybrid orbital model of bonding. www.chem1.com /acad/webtext/chembond/cb03.html   (2788 words)

The Creation The heavier neutron- proton pair of pairs of stronger bond, are closer to the nucleus core, and the lighter neutron- proton pair of pairs of weaker bond, are furthest from the nucleus. The bonding with the -E bonds the atom as a whole and weakens the centrifugal repelling force thus allowing the second bond of a pair of pairs, as will be explained in part two paragraph number 30. Not all neutron- proton pairs pair, as with the Deuterium H atom. www.shemayisrael.co.il /shure/create/create_eng_3.htm   (1853 words)

Chapter 9: Molecular Geometry and Bonding Theories Bonding pairs are attracted by the two nuclei. In an equatorial position, an electron pairs is situated 120° from the other two equatorial pairs and 90° from the two axial pairs. The energy of a bonding molecular orbital is lower than the energy of the separate atomic orbitals from which it forms. www.geocities.com /wh0ami5/htmlnotes/ch9notes.htm   (3022 words)

Chemical Bonding: polar covalence The electrons constituting a chemical bond are simultaneously attracted by the electrostatic fields of the nuclei of the two bonded atoms. This being said, it must be reiterated that the ionic model of bonding is a useful one for many purposes, and there is nothing wrong with using the term “ionic bond” to describe the interactions between the atoms in the very small class of “ionic solids” such as LiF and NaCl. Categorizing all chemical bonds as either ionic, covalent, or metallic is a gross oversimplification; as this diagram shows, there are examples of substances that exhibit varying degrees of all three bonding characteristics. www.chem1.com /acad/webtext/chembond/cb04.html   (2324 words)

curvedarrows.html The curved arrow on the left indicates the electron pair that was the O-H bond becomes a lone pair on the oxygen of the hydroxide ion. We draw a curved arrow to show the bonding electron pair between the hydrogen and oxygen of the hydronium ion moving to become the sole property of the oxygen atom. The curved arrow on the right indicates that the electron pair of the bromine-bromine bond is shifting to reside solely on the bromine on the right, resulting in rupture of the bond and formation of bromine with four lone pairs and a negative charge. web.chem.ucla.edu /~harding/tutorials/curvedarrows/curvedarrows.html   (1233 words)

ROCO Resonance: geometry 4 pairs imply a tetrahedral atom with bond angles of ~109o, 3 pairs imply a trigonal atom with bond angles of 120o, and 2 pairs imply a linear atom. Any time a N (equipped with a lone pair) lies next to a pi system, it may be possible to delocalize the N lone pair by converting it into a pi bond pair. All 6 CC bond distances are identical, and at 140 pm they lie in between the distances observed for normal CC single bonds (153 pm) and double bonds (134 pm). academic.reed.edu /chemistry/roco/Resonance/geometry.html   (1324 words)

Notes on Covalent Bonding The number of paired and unpaired electrons around an atom play an important part in determining the shape of a molecule, which in turn contribute to chemical and physical properties of the molecule. One of the simplest bonds is between hydrogen and chlorine. Carbon atoms will always have 4 bonds, either as 4 separate single bonds, or a combination of single, double and/or triple bonds so that there are 4 pairs of electrons around each carbon atom in the molecule. www.chem.vt.edu /RVGS/ACT/notes/Covalent_Bonding.html   (591 words)

The Finch Niche - Pair Bonding - Finch Behavior While watching for signs that your pair is bonding, you may also see signs the bonding isn't going as well as you had hoped. Once a pair is bonded and if the bond is strong, the pair will probably continue to breed together for many years. If you have a pair you wish to breed either for show purposes or to produce a specific color mutation it is always best to keep them in a single pair cage until they have successfully raised a clutch. www.finchniche.com /f-bonding.mgi   (731 words)

Water molecule structure In the liquid state, in spite of 80% of the electrons being concerned with bonding, the three atoms do not stay together as the hydrogen atoms are constantly exchanging between water molecules due to protonation/deprotonation processes. In a perfect tetrahedral arrangement the bond-bond, bond-lone pair and lone pair-lone pair angles would all be 109.47° and such tetrahedral bonding patterns are found in condensed phases such as hexagonal ice. Coincidentally, this diameter is similar to the length of a hydrogen bond. www.lsbu.ac.uk /water/molecule.html   (1773 words)

The neurobiology of pair bonding - Nature Neuroscience   (Site not responding. Last check: ) Pair bonding is inferred when subjects spend significantly more time in close proximity to the partner compared to the stranger (partner preference). Given this role for oxytocin and AVP in social recognition and the interaction of these peptides with mesolimbic dopamine, a reasonable hypothesis is that pair bonding results from the convergence of social discrimination circuits and the reinforcing properties of the mesolimbic dopamine reward circuit (Fig. The pair bond is an integral aspect of human sexuality with important implications for both psychological and physical health. www.nature.com /neuro/journal/v7/n10/full/nn1327.html   (5572 words)

[No title] The nitrogen-nitrogen bond lengths are identical at 1.15 A. (Typical N-N single bonds are 1.1 A, N=N double bonds are 1.20). Bonds are hybrid on single-double-triple and may not fit any exactly, but both bonds would be identical as forms b and c would occur equally. Curved arrow moves from non-bonding pair on acetone O to H on sulfuric acid, H-0 bond in sulfuric acid becomes non-bonding pair in hydrogen sulfate conjugate base. academic.evergreen.edu /curricular/m2o2001/jimexamkey.doc   (1300 words)

Perspectives on human attachment (pair bonding): Eve's unique legacy of a canine analogue by Ronald S. Immerman and ... However, the man-woman pair bond and man(to)child pair bond are not paralleled by any terrestrial primate nor many mammals. Hence, knowledge of primate behavior would not be predictive of the pan-human (i) social father and (ii) the extended pair bond between a man and woman (with the cultural overlay of marriage). It is suggested that female choice of mating partner shifted in the direction of a canid analogue in which men’s motivations to share resources with the female and to exhibit paternalistic behaviors were positively selected. human-nature.com /ep/articles/ep01138154.html   (4539 words)

Shapes of molecules and bond angles at Doc Brown's Chemistry Clinic. Electron pair repulsion theory learn learning ... The 'groups' might be a non-bonding single electron, a non-bonding or bonding pair of electrons, a double pair of bonding electrons or triple pair of bonding electrons etc. The electron 'groupings' repel to minimise the potential energy of the system i.e. In the diagrams the central atom is denoted by X and attached surrounding bonded atoms by Q. The bond angle is therefore based on angle between the atoms Q-X-Q. This is known as THE ELECTRON PAIR REPULSION THEORY. Any lone pairs of non-bonding electrons on the central atom X, are closer to X than bond pairs because there is no Q atom attracting/sharing the lone pair electron charge. www.wpbschoolhouse.btinternet.co.uk /page06/molecule_shapes.htm   (1256 words)

shapes of molecules and ions containing single bonds Lone pairs are in orbitals that are shorter and rounder than the orbitals that the bonding pairs occupy. In this diagram, two lone pairs are at 90° to each other, whereas in the other two cases they are at more than 90°, and so their repulsions can be ignored. The bond pairs are at an angle of 120° to each other, and their repulsions can be ignored. www.chemguide.co.uk /atoms/bonding/shapes.html   (2259 words)

Duran: Chapter Eleven Covalent Bonds   (Site not responding. Last check: ) - The valence electrons involved in the bond are called the bonding electrons or the bond pair, those not involved in the bond are called the nonbonding electrons or the lone pairs. As discussed in lecture true nonpolar covalent bonds only form when diatomic molecules are formed from 2 identical atoms; otherwise polar covalent bonds form. These classification schemes are useful in predicting the type of bonding which is likely to occur in a given pair of bonding atoms. www.chem.ufl.edu /~chm2040/Notes/Chapter_11/covalent.html   (614 words)

The Carbon-Lithium Electron Pair Bond in (CH3Li)n (n = 1, 2, 4) The low-energy lithium 2p orbitals are shown to play an active role in the bonding of the methyllithium aggregates and can be viewed as valence orbitals. A detailed analysis of the carbon-lithium bonding mechanism highlights the significant role of covalent contributions. the carbon-lithium bond is provided by two distinct orbital interactions: (1) an essentially covalent electron pair bond between the strongly sp hybridized Li-Li and C-C bonding fragment orbitals of the lithium cluster and the methyl cage, respectively, in A pubs.acs.org /cgi-bin/abstract.cgi/orgnd7/1996/15/i13/abs/om950966x.html   (362 words)

ELECTRON PAIR REPULSION THEORY- HYBRID ORBITAL MODEL These bond pairs are known as active set of electrons. The force of repulsion between lone pairs and bond pairs is not the same. Pi-electron pairs are not considered as an active set of electrons. www.citycollegiate.com /hybridization3.htm   (327 words)

Bonhams 1793: Fine Art Auctioneers & Valuers The second South African art sale at Bonhams New Bond Street, January 30 2008, will be the most valuable auction of South African art ever held. The work illustrated, by Irma Stern, 'Portrait of a Pondo Woman', dates from 1929 and comes from a period in Stern's work when she was exploring the differences in appearance and dress found in the African tribal women. It is to sell on 19 December at 2pm at New Bond Street, London. www.bonhams.com   (266 words)

ScienceDaily: Reward Mechanism Involved In Addiction Likely Regulates Pair Bonds Between Monogamous Animals ATLANTA -- The reward mechanism involved in addiction appears to regulate lifelong social or pair bonds between monogamous mating animals, according to a Center for Behavioral Neuroscience (CBN) study of prairie voles published in the January 19 edition of the Journal of Comparative Neurology. V1aR receptors, which are thought to be activated in the male vole brain during pair bond formation, were confined largely to the ventral pallidum. OTR receptors, which play a crucial role in pair bond formation in females, were found mainly in the nucleus accumbens. www.sciencedaily.com /releases/2004/01/040121074745.htm   (1943 words)

Chemical bond   (Site not responding. Last check: ) Covalent bonds are the most important type of bond occurring in organic molecules chemical bond.. A chemical bond that involves sharing a pair of electrons between atoms in a. A Covalent Bond is a bond formed by the sharing of one, two or three pairs of electrons by two atoms chemical bond.. www.bankark.com /chemical-bond.html   (300 words)

Common Loon Detailed Information - Montana Animal Field Guide It is believed that pairs re-mate each spring and that courtship serves primarily to renew the pair bond (McIntyre 1988). Nest-building is conducted by both members of the pair and may immediately follow copulation, sometimes lasting over four days (McIntyre 1975, 1988). Both pair members incubate, beginning with the laying of the first egg, for an average period of 28-29 days, ranging from 26-31 days (Bent 1919, Olson and Marshall 1952, Palmer 1962, McIntyre 1975). fwp.mt.gov /fieldguide/detail_ABNBA01030.aspx   (3293 words)

Spotlight on Birds - Smithsonian Migratory Bird Center - National Zoo| FONZ   (Site not responding. Last check: ) Most birds nest as monogamous pairs but young may, or may not, be fathered by the male of the pair. When the young are his, the pair bond is said to be genetically monogamous but, if some are not his, the pair bond is socially monogamous but not genetically so. A key requirement for males is to have many females nearby in the egg-laying stage because a female that has laid her eggs is no longer fertilizable. nationalzoo.si.edu /ConservationAndScience/MigratoryBirds/Science_Article/default.cfm?id=17   (1010 words)

Valence bond theory summary The theory underlying the Lewis electron pair bond concept is valence bond theory. The simplest possible electron pair bond would occur in H (2) would be the 1s orbitals of hydrogen, but, in principle, this mathematical treatment could be adapted for an electron pair bond between any two atoms by using the appropriate atomic or hybrid orbitals.) alcor.concordia.ca /~birdp/v-bond_theory.html   (270 words)

Facilitation of Affiliation and Pair-Bond Formation by Vasopressin Receptor Gene Transfer into the Ventral Forebrain of ... The role of AVP in facilitating pair bonding in the male prairie vole is remarkably parallel to that of oxytocin in the female Liu Y, Curtis JT, Wang ZX (2001) Vasopressin in the lateral septum regulates pair bond formation in male prairie voles (Microtus ochrogaster). Winslow J, Hastings N, Carter CS, Harbaugh C, Insel T (1993) A role for central vasopressin in pair bonding in monogamous prairie voles. www.jneurosci.org /cgi/content/full/21/18/7392   (4645 words)

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