Heat capacity is an extensive property of matter, meaning it is proportional to the size of the system. Heat capacity C has the unit of energy per degree or energy per kelvin. When expressing the same phenomenon as an intensive property , the heat capacity is divided by the amount of substance, mass, or volume, thus the quantity is independent of the size or extent of the sample. In general, when a material changes phase from solid to liquid, or from liquid to gas a certain amount of energy is involved in this change of phase.
As an example, see the figure, which descibes phase transitions of water. Latent heat is the amount of heat added to or removed from a substance to produce a change in phase. When latent heat is added, no temperature change occurs.
The enthalpy of vaporization is a function of the pressure at which that transformation takes place. The liquid phase has a higher internal energy than the solid phase. This means energy must be supplied to a solid in order to melt it and energy is released from a liquid when it freezes, because the molecules in the liquid experience weaker intermolecular forces and so have a higher potential energy a kind of bond-dissociation energy for intermolecular forces.
The enthalpy of fusion is a function of the pressure at which that transformation takes place. By convention, the pressure is assumed to be 1 atm Search Search.
What is Ytterbium Ytterbium is a chemical element with atomic number 70 which means there are 70 protons and 70 electrons in the atomic structure. There are two reasons for the difference between mass number and isotopic mass, known as the mass defect : The neutron is slightly heavier than the proton.
This increases the mass of nuclei with more neutrons than protons relative to the atomic mass unit scale based on 12 C with equal numbers of protons and neutrons. The nuclear binding energy varies between nuclei.
For 63 Cu the atomic mass is less than 63 so this must be the dominant factor. Typical densities of various substances at atmospheric pressure. Electronegativity of Ytterbium is —.
Affinities of Non metals vs. Affinities of Metals Metals: Metals like to lose valence electrons to form cations to have a fully stable shell. The electron affinity of metals is lower than that of nonmetals. Mercury most weakly attracts an extra electron. Nonmetals: Generally, nonmetals have more positive electron affinity than metals. Nonmetals like to gain electrons to form anions to have a fully stable electron shell. Chlorine most strongly attracts extra electrons. The electron affinities of the noble gases have not been conclusively measured, so they may or may not have slightly negative values.
Moreover: Ionization energy is lowest for the alkali metals which have a single electron outside a closed shell. Ionization energy increases across a row on the periodic maximum for the noble gases which have closed shells. Boiling Point — Saturation In thermodynamics, the term saturation defines a condition in which a mixture of vapor and liquid can exist together at a given temperature and pressure.
Melting Point — Saturation In thermodynamics, the melting point defines a condition in which the solid and liquid can exist in equilibrium. Latent Heat of Fusion of Ytterbium is 7. Latent Heat of Vaporization of Ytterbium is Specific Heat Specific heat , or specific heat capacity, is a property related to internal energy that is very important in thermodynamics.
The intensive properties c v and c p are defined for pure, simple compressible substances as partial derivatives of the internal energy u T, v and enthalpy h T, p , respectively: where the subscripts v and p denote the variables held fixed during differentiation.
Latent Heat of Vaporization In general, when a material changes phase from solid to liquid, or from liquid to gas a certain amount of energy is involved in this change of phase.
The temperature at which the phase transition occurs is the melting point. Boron 5 B. For 63 Cu the atomic mass is less than 63 so this must be the dominant factor. Typical densities of various substances at atmospheric pressure.
Boron 5 B. Carbon 6 C. Neon 10 Ne. Sulfur 16 S. Argon 18 Ar. Iron 26 Fe. Cobalt 27 Co. Nickel 28 Ni. Copper 29 Cu. Zinc 30 Zn. Gallium 31 Ga. Arsenic 33 As.
Bromine 35 Br. Yttrium 39 Y. Silver 47 Ag. Seven naturally occurring isotopes of ytterbium are known ranging from mass numbers to In addition, ten radioactive isotopes are also known; these isotopes are unstable and break down into other isotopes giving out radiation in the process.
Ytterbium in particular emits gamma rays. Gamma rays are similar to X-rays in that they pass through soft materials and tissues but are blocked by more dense materials such as bone. In this regard, small amounts of Yb have been exploited in portable X-ray machines that require no electricity and are much easier to carry around than conventional X-ray machines-useful for radiography of small objects! A second intriguing possibility is the use of elemental ytterbium is in super accurate atomic clocks.
The isotope Yb has the potential to keep time more accurately than the current gold standard, which is a caesium fountain clock that is accurate to within a second every million years. Then no one will have any excuse for being late! The only ytterbium compound of historical commercial use is ytterbium oxide Yb2O3 ; this is used to make alloys and special types of glass and ceramics.
These special materials or phosphors are being devised as alternatives to europium and terbium phosphors in anti forgery security inks and in bank notes.
Instead of placing the bank note under UV light to see the security encoding, an infra red laser pen is used to reveal the luminescence colours of erbium, clever hey? Terbium compounds are currently used as luminescent probes in biological and biomedical research, but they emit visible light.
In the research community, luminescent ytterbium compounds that give out light in the near infra red around nm are of current interest and are being developed for use as alternative luminescent probes. This means, that unlike Eu or Tb, which emit visible light, the light is in invisible to our eyes. Human tissue is a lot more transparent to near infra red radiation than to visible light, which means that imaging with near infra red would access greater tissue depths and so give us more detailed information regarding a specific biological event or process.
Ytterbium is also used in some laser systems and ytterbium fibre laser amplifiers are found in commercial and industrial applications where they are used in marking and engraving. Ytterbium compounds are capable of absorbing light in the near infra red part of the electromagnetic spectrum, which has been exploited to convert radiant energy into electrical energy in devices coupled to solar cells. Additionally, ytterbium compounds are often more potent catalysts than their lanthanide counterparts.
They are useful for many organic transformations and are finding increasing use in the chemical industry. Well, that was ytterbium, definitely an interesting and fascinating element with many uses as diverse as atomic clocks and solar cells and definitely different from the other lanthanides.
Different indeed with that range of uses. That was Manchester University's Louise Natrajan with the unique chemistry of ytterbium.
Now next week, we've got an explosive element and I'll give one you guess as to who it's named after. When the bomb exploded on November the first, , it produced an explosion with the power of over 10 million tonnes of TNT - five hundred times the destructive power of the Nagasaki explosion. This was very much a test device - weighing over 80 tons and requiring a structure around 50 feet high to support it, meaning that it could never have been deployed - but it proved, all too well, the capability of the thermonuclear weapon.
And in the moments of that intense explosion it produced a brand new element. There among the ash and charred remains of coral were found a couple of hundred atoms of element 99, later to be called einsteinium. Brian Clegg will be providing more insight into the reactions and naming of einsteinium in next week's Chemistry in its element. Until then I'm Meera Senthilingam and thank you for listening. Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists.
There's more information and other episodes of Chemistry in its element on our website at chemistryworld. Click here to view videos about Ytterbium.
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Data W. Haynes, ed. Version 1. Coursey, D. Schwab, J. Tsai, and R. Dragoset, Atomic Weights and Isotopic Compositions version 4. Periodic Table of Videos , accessed December Podcasts Produced by The Naked Scientists. Download our free Periodic Table app for mobile phones and tablets.
Explore all elements. D Dysprosium Dubnium Darmstadtium. E Europium Erbium Einsteinium. F Fluorine Francium Fermium Flerovium. G Gallium Germanium Gadolinium Gold.
I Iron Indium Iodine Iridium. K Krypton. O Oxygen Osmium Oganesson. U Uranium. V Vanadium. X Xenon. Y Yttrium Ytterbium. Z Zinc Zirconium. Membership Become a member Connect with others Supporting individuals Supporting organisations Manage my membership. Facebook Twitter LinkedIn Youtube. Discovery date. Discovered by. Jean Charles Galissard de Marignac. Origin of the name. Ytterbium is named after Ytterby, Sweden. Melting point.
Boiling point. Atomic number. Relative atomic mass. Key isotopes. Electron configuration. CAS number. ChemSpider ID. ChemSpider is a free chemical structure database. Electronegativity Pauling scale. Common oxidation states.
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