A bond strength is also a bonds energy this is referred to as the energy that is required to break a bond between two atoms. These value often differ with covalent, metallic and ionic bonds.
In a covalent molecule we can measure the strength it takes to break the bond. We measure this energy in kj/mol which is the amount of energy in kilojoules it takes per mole of substance. This value is often averaged over a range of compounds due to the influence of different atoms on these bonds with electronegativities. For example the energy required to break the bond between carbon and hydrogen atoms is 415KJ/mol but this bond energy would be different depending on what other atoms are bonded to the carbon.
The strength of a bond between two atoms is also influenced by the number of electron pairs. For example when two atoms share one pair of electrons this is called a single bond, but when a par of atoms share two pairs of electrons this is a double bond. When comparing a single bond to a double bond, double bonds require a lot more energy to break the bond between the two atoms. For example a nitrogen bonded to another nitrogen can have different bond strengths based on how many bonds it has between the atoms. A nitrogen that is double bonded requires 418KJ/mol where as a single bonded nitrogen molecule requires 160KJ/mol.
Bond strength is also often related to bond length the shorter a bond in general the stronger it is. This is evident when looking at the trend in bond energies down a group as in general down a group the atoms increase in size and the nucleus is further away from the bonded electrons. For example looking at the bon between a carbon atom and different halogens we can see a trend. The bond between carbon and fluorine requires 439kj/mol of energy to break the bond compared to the bond between carbon and bromine which requires 275kj/mol. This is because the bromine atom is much larger in size compared to the fluorine atom.
When measuring the bond energy in ionic compounds the energy that it takes to break apart the lattice structure of an ionic compound. Separating ionic compounds from their lattices is an endothermic process requiring energy to be put in. The amount of energy required to break apart a lattice depends on the size of the ion and charge of the ions involved in the lattice. For example the lattice of lithium fluoride contains a lithium atom with a +1 charge and a fluoride atom with a -1 charge. This lattice requires 1023 Kj/mol to separate the ions. This is compared to 3900Kj/mol of energy required to separate the lattice of magnesium oxide where the magnesium ion has a +2 charge and the oxygen has a -2 charge. This shows that the larger the charge on the ions the more energy is required to break apart the lattice.
Nathan has a degree in BSc Biomedical Chemistry at Warwick University and a degree in PGCE Science at Wolverhampton University, UK. Nathan's subject matter ranges from general chemistry and organic chemistry. Nathan also created the curriculum on Breaking Atom in the course page.
Corpuscularism was a theory proposed by Descartes that all matter was composed of tiny particles.
Rene Descartes was a famous mathematician and philosopher of the 16th century who hypothesised the theory of corpuscularism about the atom
Luster is a term for a reflective surface that reflects light giving a shiny appearance.
Semi conductors is a term to describe metalloids that are able to conduct a current when electrical energy is applied due to the movement of electrons but the conductivity measurements are not as high as metals due to fewer electrons to carry a charge or a less ordered structure.
An ionic compound is a bond that forms between metals and non metals to form a large ionic lattice
Nuclear fusion is a process which occurs in. the sun. Hydrogen atoms under a lot of heat and pressure are forced together to make a larger atom of helium
Heisenberg’s uncertainty principle is used to describe the relationship between the momentum and position of an electron. Where by if the exact position of the electron is known the momentum will be uncertain.
Werner Heisenberg was a German physicist who was a pioneer in the field of quantum mechanics. He devised the principle of uncertainty relating to the momentum and position of an electron.
Lobes refers to the shape of electron waves and the area of highest probability of where that electron as a particle would be found.
The Pauli Exclusion refers to the theory that each electron can only have a unique set of the 4 quantum numbers and no two electrons can have the same quantum numbers
Quantum numbers is a term used to describe the assigning of numbers to electrons as a mathematical function to describe their momentum and energy.
The Bohr model refers to the treatment of electrons as particles that orbit the nucleus.
The term quantum mechanics refers to energy levels and the theoretical area of physics and chemistry where mathematics is used to explain the behaviour of subatomic particles.
A trough is the lowest point on a transverse wave.
A peak is the highest point on a transverse wave.
Vibrational modes is a term used to describe the constant motion in a molecule. Usually these are vibrations, rotations and translations.
Erwin Schrodinger was an Austrian physicist who used mathematical models to enhance the Bohr model of the electron and created an equation to predicted the likelihood of finding an electron in a given position.
The alkali metals, found in group 1 of the periodic table (formally known as group IA), are so reactive that they are generally found in nature combined with other elements. The alkali metals are shiny, soft, highly reactive metals at standard temperature and pressure.
Alkaline earth metals is the second most reactive group of elements in the periodic table. They are found in group 2 of the periodic table (formally known as group IIA).
Unknown elements (or transactinides) are the heaviest elements of the periodic table. These are meitnerium (Mt, atomic number 109), darmstadtium (Ds, atomic number 110), roentgenium (Rg, atomic number 111), nihonium (Nh, atomic number 113), moscovium (Mc, atomic number 115), livermorium (Lv, atomic number 116) and tennessine (Ts, atomic number 117).
The post-transition metals are the ones found between the transition metals (to the left) and the metalloids (to the right). They include aluminium (Al), gallium (Ga), indium (In), thallium (Tl), tin (Sn), lead (Pb) and bismuth (Bi).
Oganesson (Og) is a radioactive element that has the atomic number 118 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is in Group 18. It has the symbol Og.
Tennessine (Ts) is a radioactive element that has the atomic number 117 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is in Group 17. It has the symbol Ts.
Livermorium (Lv) is a radioactive element that has the atomic number 116 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is in Group 16. It has the symbol Lv.
Moscovium (Mc) is a radioactive metal that has the atomic number 115 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is in Group 15. It has the symbol Mc.
Flerovium (Fl) is a radioactive metal that has the atomic number 114 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is in Group 14. It has the symbol Fl.
Nihonium (Nh) is a radioactive metal that has the atomic number 112 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is in Group 13. It has the symbol Nh.
Copernicium (Cr) is a radioactive metal that has the atomic number 112 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 11. It has the symbol Rg.
Roentgenium (Rg) is a radioactive metal that has the atomic number 111 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 11. It has the symbol Rg.
Darmstadtium (Ds) is a radioactive metal that has the atomic number 110 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 10. It has the symbol Ds
Meitnerium (Mt) is a radioactive metal that has the atomic number 109 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 9. It has the symbol Mt.
Hassium (Hs) is a radioactive metal that has the atomic number 108 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 8. It has the symbol Hs.
Bohrium (Bh) is a radioactive metal that has the atomic number 107 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 7. It has the symbol Bh.
Seaborgium (Sg) is a radioactive metal that has the atomic number 106 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 6. It has the symbol Sg.
Dubnium (Db) is a radioactive metal that has the atomic number 105 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 5. It has the symbol Db.
Rutherfordium (Rf) is a radioactive metal that has the atomic number 104 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is a Transition metal in Group 4. It has the symbol Rf.
Lawrencium (Lr) is a silvery-white colored radioactive metal that has the atomic number 103 in the periodic table. It is an Actinoid Metal with the symbol Lr.
Nobelium (No) is a radioactive metal that has the atomic number 102 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is an Actinoid Metal with the symbol No.
Mendelevium (Md) is a radioactive metal that has the atomic number 101 in the periodic table, its appearance is not fully known due to the minuscule amounts produced of it. It is an Actinoid Metal with the symbol Md.
Fermium (Fm) is a silvery-white colored radioactive metal that has the atomic number 100 in the periodic table. It is an Actinoid Metal with the symbol Fm.
Einsteinium (Es) is a silvery-white colored radioactive metal that has the atomic number 99 in the periodic table. It is an Actinoid Metal with the symbol Es.
Californium (Cf) is a silvery-white colored radioactive metal that has the atomic number 98 in the periodic table. It is an Actinoid Metal with the symbol Cf.
Berkelium (Bk) is a silvery colored radioactive metal that has the atomic number 97 in the periodic table. It is an Actinoid Metal with the symbol Bk.
Curium (Cm) is a silvery-white colored radioactive metal that has the atomic number 96 in the periodic table. It is an Actinoid Metal with the symbol Cm.
Americium (Am) is a silvery colored radioactive metal that has the atomic number 95 in the periodic table. It is an Actinoid Metal with the symbol Am.
Plutonium (Pu) is a silvery colored radioactive metal that has the atomic number 94 in the periodic table. It is an Actinoid Metal with the symbol Pu.
Neptunium (Np) is a silvery colored radioactive metal that has the atomic number 93 in the periodic table. It is an Actinoid Metal with the symbol Np.
Protactinium (Pa) is a shiny silver colored radioactive metal that has the atomic number 91 in the periodic table. It is an Actinoid Metal with the symbol Pa.
Thorium (Th) is a silvery-white colored radioactive metal that has the atomic number 90 in the periodic table. It is an Actinoid Metal with the symbol Th.
Actinium (Ac) is a silvery colored radioactive metal that has the atomic number 89 in the periodic table. It is an Actinoid Metal with the symbol Ac.
Radium (Ra) is a silvery-white colored metal that has the atomic number 88 in the periodic table. It is an Alkaline earth Metal with the symbol Ra and is located in Group 2 of the periodic table.
Francium (Fr) is thought to be a gray colored metal that has the atomic number 87 in the periodic table. It is an Alkali Metal with the symbol Fr and is located in Group 1 of the periodic table.
Radon (Rn) is a colourless, odourless, radioactive gas non-metal that has the atomic number 86 in the periodic table in Group 18. It has the symbol Rn.
Astatine (At) is a radioactive non-metal that has the atomic number 85 in the periodic table in Group 17. It has the symbol At.
Polonium (Po) is a silvery-gray metal that has the atomic number 84 in the periodic table in Group 16. It has the symbol Po.
Bismuth (Bi) is a hard steel-gray metal that has the atomic number 83 in the periodic table in Group 15. It has the symbol Bi.
Lead (Pb) is a soft gray metal that has the atomic number 82 in the periodic table in Group 14. It has the symbol Pb.
Thallium (Tl) is a soft gray metal that has the atomic number 81 in the periodic table in Group 13. It has the symbol Tl.
Mercury (Hg) is a liquid silver coloured metal that has the atomic number 80 in the periodic table. It is a Transition metal in Group 12. It has the symbol Hg.
Gold (Au) is a soft gold coloured metal that has the atomic number 79 in the periodic table. It is a Transition metal in Group 11. It has the symbol Au.
Platinum (Pt) is a heavy white metal that has the atomic number 78 in the periodic table. It is a Transition metal in Group 10. It has the symbol Pt.
Iridium (Ir) is a heavy white metal that has the atomic number 77 in the periodic table. It is a Transition metal in Group 9. It has the symbol Ir.
Osmium (Os) is a hard fine black powder or blue-white metal that has the atomic number 76 in the periodic table. It is a Transition metal in Group 8. It has the symbol Os.
Rhenium (Re) is a silvery-white coloured metal that has the atomic number 75 in the periodic table. It is a Transition metal in Group 7. It has the symbol Re.
Tungsten (W) is a steel-gray coloured metal that has the atomic number 74 in the periodic table. It is a Transition metal in Group 6. It has the symbol W.
Tantalum (Ta) is a gray coloured metal that has the atomic number 73 in the periodic table. It is a Transition metal in Group 5. It has the symbol Ta.
Hafnium (Hf) is a silvery coloured metal that has the atomic number 72 in the periodic table. It is a Transition metal in Group 4. It has the symbol Hf.
Lutetium (Lu) is a silvery-white coloured metal that has the atomic number 71 in the periodic table. It is a Lanthanide metal. It has the symbol Lu.
Ytterbium (Yb) is a silvery coloured metal that has the atomic number 70 in the periodic table. It is a Lanthanide metal. It has the symbol Yb.
Thulium (Tm) is a silvery coloured metal that has the atomic number 69 in the periodic table. It is a Lanthanide metal. It has the symbol Tm.
Erbium (Er) is a silvery coloured metal that has the atomic number 68 in the periodic table. It is a Lanthanide metal. It has the symbol Er.
Holmium (Ho) is a silvery coloured metal that has the atomic number 67 in the periodic table. It is a Lanthanide metal. It has the symbol Ho.
Dysprosium (Dy) is a silvery coloured metal that has the atomic number 66 in the periodic table. It is a Lanthanide metal. It has the symbol Dy.
Terbium (Tb) is a silvery-gray coloured metal that has the atomic number 65 in the periodic table. It is a Lanthanide metal. It has the symbol Tb.
Gadolinium (Gd) is a silvery-white coloured metal that has the atomic number 64 in the periodic table. It is a Lanthanide metal. It has the symbol Gd.
Europium (Eu) is a silvery-white coloured metal that has the atomic number 63 in the periodic table. It is a Lanthanide metal. It has the symbol Eu.
Samarium (Sm) is a silvery coloured metal that has the atomic number 62 in the periodic table. It is a Lanthanide metal. It has the symbol Sm.
Promethium (Pm) is a rare metal that has the atomic number 61 in the periodic table. It is a Lanthanide metal. It has the symbol Pm.
Neodymium (Nd) is a silvery white coloured metal that has the atomic number 60 in the periodic table. It is a Lanthanide metal. It has the symbol Nd.
Praseodymium (Pr) is a silvery white coloured metal that has the atomic number 59 in the periodic table. It is a Lanthanide metal. It has the symbol Pr.
Cerium (Ce) is a iron-gray coloured metal that has the atomic number 58 in the periodic table. It is a Lanthanide metal. It has the symbol Ce.
Lanthanum (La) is a soft silvery white coloured metal that has the atomic number 57 in the periodic table. It is a Lanthanide metal. It has the symbol La.
Barium (Ba) is a soft silvery white coloured metal that has the atomic number 56 in the periodic table. It is an Alkaline earth metal and is located in Group 2 of the periodic table. it has the symbol Ba.
Caesium (Cs) is a soft gray coloured metal that has the atomic number 55 in the periodic table. It is an Alkali Metal and is located in Group 1 of the periodic table. it has the symbol Cs.
Xenon (Xe) exists as a colourless, odourless gas and is chemically inert. It has the atomic number 54 in the periodic table and belongs in Group 18, the Noble Gases. It is a non metal with the symbol Xe.
Iodine (I) is a purple grey solid non metal. It has the atomic number 53 in the periodic table. It is located in Group 17, the Halogens. It has the symbol I.
Tellurium (Te) is a silver-white semi metal that has the atomic number 52 in the periodic table. It is located in Group 16 of the periodic table. It has the symbol Te.
Antimony (Sb) is a hard brittle silver-white semi metal that has the atomic number 51 in the periodic table. It is located in Group 15 of the periodic table. It has the symbol Sb.
Tin (Sn) is a silver-white metal that has the atomic number 50 in the periodic table. It is located in Group 14 of the periodic table. It has the symbol Sn.
Indium (In) is a silver-white metal that has the atomic number 49 in the periodic table. It is located in Group 13 of the periodic table. It has the symbol In.
Cadmium (Cd) is a blue-white metal that has the atomic number 48 in the periodic table. It is a Transition metal and located in Group 12 of the periodic table. It has the symbol Cd.
Silver (Ag) is a silver metal that has the atomic number 47 in the periodic table. It is a Transition metal and located in Group 11 of the periodic table. It has the symbol Ag.
Palladium (Pd) is a silver-white metal that has the atomic number 46 in the periodic table. It is a Transition metal and located in Group 10 of the periodic table. It has the symbol Pd.
Rhodium (Rh) is a brittle silver-white metal that has the atomic number 45 in the periodic table. It is a Transition metal and located in Group 9 of the periodic table. It has the symbol Rh.
Ruthenium (Ru) is a brittle silver-gray metal that has the atomic number 44 in the periodic table. It is a Transition metal and located in Group 8 of the periodic table. It has the symbol Ru.
Technetium (Tc) is a silvery-gray metal that has the atomic number 43 in the periodic table. It is a Transition metal and located in Group 7 of the periodic table. It has the symbol Tc.
Molybdenum (Mo) is a silvery-white metal that has the atomic number 42 in the periodic table. It is a Transition metal and located in Group 6 of the periodic table. It has the symbol Mb.
Niobium (Nb) is a shiny white metal that has the atomic number 41 in the periodic table. It is a Transition metal and located in Group 5 of the periodic table. It has the symbol Nb.
Zirconium (Zr) is a gray white metal that has the atomic number 40 in the periodic table. It is a Transition metal and located in Group 4 of the periodic table. It has the symbol Zr.
Yttrium (Y) is a silvery metal that has the atomic number 39 in the periodic table. It is a Transition metal and located in Group 3 of the periodic table. It has the symbol Y.