Nature has 10,000 different inorganic and 10^11 different organic compounds {molecule}|. People know properties of 10^9 molecules.
color
Metal complexes can have metal ions with d orbitals, which chemically bind other molecules at smaller energy levels than s or p orbitals, lowering energy levels to visible light range, from ultraviolet for s and p orbitals. Iron compounds are red. Cobalt compounds are blue. Nickel compounds are green. Copper compounds are blue or green. Lead compounds are white. Silver compounds are black.
Organic molecules can have conjugated double bonds, which spread electron-orbital energies and lower energy levels to visible-light range, from ultraviolet for single bonds. Organic dyes and indicators have long carbon sequences and have lowest light frequencies, from red to blue.
diameter
Molecules have diameters from 10^-8 centimeters to 10^-5 centimeter. In periodic-table rows, right-most atom is half left-most-atom diameter. Last-row atom diameter is much greater than first-row atom diameter.
electrical property
Atom diameter and proton number determine electrical properties. Diameter changes have more effect than proton-number changes. Noble gases have lowest electron affinity and highest ionization energy, because electron shells are full. Elements in top-right periodic table have highest electron affinity and highest ionization energy, because they have relatively small diameter and relatively large proton number.
Substances {compound, chemistry}| can have different atoms bound together.
In molecules, atom atomic-weight sum is molecule mass {molecular weight}| {formula mass} {molecular mass}, in atomic mass units.
In compounds, element percentage {percent composition} is atomic mass, in atomic mass units, multiplied by number of atoms, divided by molecular weight, in atomic mass units.
High-temperature superconductors {strange metal state} {bad metal} can have impurities.
Ions {complex ion} can have more than one atom. Complex ions typically have central positive atom {mononuclear atom}. Mononuclear atom binds to negative atom ligands. Ligands can chelate to central atom at two or more sites.
properties
Central atom can have high charge, small radius, and filled or half-filled d orbitals. Central atom can have low charge, large radius, and odd number of d-orbital electrons. If central atom has higher positive charge, greater atomic weight, and/or more electrons in d orbitals, complex ion is more stable. d orbitals are most stable when they are half full or have 3, 6, or 8 electrons.
types
Heme has iron as central atom. Chlorophyll has magnesium as central atom. Vitamin B12 has cobalt as central atom.
In covalent compounds, ionization potential is inversely proportional to half the distance {effective atomic radius} between two covalently bound nuclei. Effective atomic radius ranges from 0.037 nanometers to 0.3 nanometers.
In gases, atoms have potential energies, which range from -0.9 eV to +3.6 eV, to attract additional electrons {electron affinity}. Atom electronegativity directly correlates with electron affinity.
Atomic nuclei attract electrons in shared orbitals {electronegativity}. Electronegativity is proportional to sum of ionization potential and electron affinity.
energy
For two bonded atoms, electronegativity difference is proportional to square root of bond-energy ionic bonding part {partial ionic character}, which ranges from 0.8 eV to 4.0 eV.
bonds
If both atoms have high electronegativity, they have covalent bonding. If both atoms have low electronegativity, they have metallic bonding. If one atom has high electronegativity and one atom has low electronegativity, they have ionic bonding.
location
Atom with higher electronegativity has higher probability of containing bonding electrons, and lower probability of containing antibonding electrons, than other atom.
To remove outermost electron, gas atoms require energy {ionization potential} {ionization energy}, which ranges from 4 eV to 24 eV.
Dots can represent electrons in molecule electron structures {Lewis structure}. Atoms, except hydrogen with two dots, have eight dots, to represent electrons in outer shell. Two dots are at atom right, bottom, left, or top. If two atoms bond, two dots are between them. If two atoms have double bond, four dots are between them.
Molecules {radical, molecule}| {free radical} can have no charge but have only one unpaired electron in outer orbital. Peroxides have oxygen free radicals. When peroxide or double-bonded carbon binds to carbon, carbon atom can have free radical.
Two non-metal-atom electrons {unshared pair} can be in non-bonding outer-shell orbital.
Atoms have number {valence, atom}| of outer-shell electrons, or missing outer-shell electrons, needed to complete outer shell.
Atom rotational, vibrational, and translational energy modes have same energy {energy partition} {partition of energy, chemistry}. If energy is different, rotation or vibration gains or loses energy to neighboring rotations and vibrations and returns to equilibrium.
Molecular groups can rotate around single bonds {rotation, bond}. Double bonds, triple bonds, and bonds with resonance have no rotation.
types
Because spherical molecules are symmetric in all three space directions, spherical molecules have no net rotation. Spin around axis leaves molecule the same. Spherical molecules cannot rotate around axis that does not go through center.
Linear molecules can spin around axis perpendicular to chemical bond, so linear molecules can have net rotation. Because linear molecules are symmetric in one space direction, linear molecules have no net rotation around line between nuclei, because spin around that axis leaves molecule the same.
Molecules that are not spherical or linear have no symmetry axis and can rotate around three mutually perpendicular space dimensions.
Molecule bonds can have different vibration types {vibration, molecule}.
types
Vibrations can stretch and compress chemical bonds along line between nuclei. Vibrations can widen and narrow angle between two bonds.
number
Molecules with no bonds cannot vibrate.
Molecules with one bond have one vibration type, bond compressing and stretching.
Molecules with two bonds can have four vibration modes. One bond can stretch, as the other compresses. Both bonds can stretch and compress at same time. Angle between bonds can narrow and widen. One bond can move downward perpendicular to bond plane, while one moves upward perpendicular to bond plane.
symmetry
Molecule symmetries can make two vibration modes indistinguishable and decrease total number of vibration modes.
Compounds {binary compound} {diatomic compound} can have two different elements. Hydrofluoric acid, for glass etching, is HF. The strong acid hydrochloric acid is HCl.
Table salt is NaCl. Sodium fluoride toothpaste compound is NaF. Sodium-bromide stomach soother is NaBr. Sodium iodide iodizing salt is NaI. Potassium chloride salt substitute is KCl.
Poisonous colorless odorless carbon monoxide gas is CO. The poisonous gas nitric oxide is NO. Calcium oxide, lime fertilizer, is CaO. Bronze green color, cupric oxide, is CuO. The solid used in flat stovetops, magnesium oxide, is MgO.
Compounds {triatomic compound} can have three atoms.
Water is H2O [2 is subscript].
Colorless odorless carbon dioxide gas, from burning, is CO2 [2 is subscript].
Inefficient burning makes nitrogen dioxide gas, NO2 [2 is subscript]. The colorless anesthetic gas nitrous oxide is N2O [2 is subscript].
Gas with rotten egg smell, hydrogen sulfide, is H2S [2 is subscript]. The irritating gas for preserving food and for refrigeration, sulfur dioxide, is SO2 [2 is subscript].
Lye or sodium hydroxide strong base is NaOH. The strong base potassium hydroxide is KOH. Milk of magnesia or magnesium hydroxide antacid is MgOH. Slaked lime mortar, calcium hydroxide, is CaOH.
Potash or potassium oxide fertilizer is K2O [2 is subscript].
Calcium chloride drying agent is CaCl2 [2 is subscript], for icy roads.
Black silver tarnish, silver oxide, is Ag2O [2 is subscript].
Hydrogen cyanide poisonous gas is HCN. Silicon-oxide glass is SiO2 [2 is subscript].
Black car-battery-terminal coating, lead oxide, is PbO2 [2 is subscript].
Bleach or sodium hypochlorite is NaClO.
Compounds {polyatomic compound} can have more than three atoms.
organic
Natural gas or methane is CH4 [4 is subscript]. Artificial gas or propane is C3H8 [3 and 8 are subscripts]. Lighter fluid or butane is C4H10 [4 and 10 are subscripts].
Carbon tetrachloride solvent is CCl4 [4 is subscript]. Chloroform anesthetic is CH3Cl [3 is subscript].
The strong base-forming gas ammonia is NH3 [3 is subscript].
Hydrogen peroxide disinfectant is H2O2 [2 is subscript].
iron
Rust or iron oxide is Fe2O3 [2 and 3 are subscripts]. Magnetite iron ore, iron (II) oxide, is FeO. Hematite iron ore, iron (III) oxide, is Fe2O3 [2 and 3 are subscripts].
calcium
Limestone, chalk, and the cement ingredient calcium carbonate is CaCO3 [3 is subscript]. Calcium phosphate bone mineral is Ca3(PO4)2 [3 and 2 are subscripts]. Plaster of paris or calcium sulfate is CaSO4 [4 is subscript].
sodium
Baking soda or sodium bicarbonate is NaHCO3 [3 is subscript]. Soda ash or sodium carbonate is Na2CO3 [2 and 3 are subscripts]. The fixer for photographic solutions, sodium thiosulfate, is NaHSO4 [4 is subscript].
alkali metals
The gunpowder and meat-curing salt saltpeter or potassium nitrate is KNO3 [3 is subscript].
The manic-depressive treatment lithium carbonate is Li2CO3 [2 and 3 are subscripts]. Lithium dialkylamides remove protons in chemical reactions.
Magnesium hydroxide antacid is Mg(OH)2 [2 is subscript]. The laxative, tanning, and dyeing compound Epsom salts or magnesium sulfate is MgSO4 [4 is subscript].
The compound used for GI tract x-rays, barium sulfate, is BaSO4 [4 is subscript].
boron
The compound used in heatproof glass, boron oxide, is B2O3 [2 and 3 are subscripts]. Boron nitride abrasive is BN3 [3 is subscript]. Borax detergent ingredient is B(C2H2O2)3 [2 and 3 are subscripts]. The abrasive carborundum or boron carbide is BC3 [3 is subscript].
aluminum
The treatment for canker sores, and compound for water purification, alum, aluminum potassium sulfate, is AlK(SO4)2 [4 and 2 are subscripts]. The white layer coating aluminum is aluminum oxide, Al2O3 [2 and 3 are subscripts], used in ceramics and abrasives. Aluminum hydroxide antacid is Al(OH)3 [3 is subscript].
copper
The blue compound copper sulfate is CuSO4 [4 is subscript]. The green compound copper chloride is CuCl2 [2 is subscript].
silver
Silver nitrate silver-plating salt is AgNO3 [3 is subscript].
The white layer coating aluminum is aluminum oxide or Al2O3 {alumina} [2 and 3 are subscripts], used in ceramics and abrasives.
Transparent brittle materials {glass}| can have different-length bonds and low thermal expansion. Sand is silicon dioxide. To make glass, melted sand receives small amounts of soda and lime at 2700 F. Melted sand is clear solid but is not crystalline. Glass does not melt at one temperature but becomes more fluid over temperature range. People can cut, blow, shape, and mold hot glass. Drawing molten glass through shaped boats floating in melted glass makes glass sheets. The glass cools slightly and then vertical rollers make it have equal thickness.
Compounds {halide} can contain fluorine, chlorine, bromine, or iodine.
Molecules {metal complex} can have metal ions with d orbitals, which chemically bind other molecules at smaller energy levels than s or p orbitals, lowering energy levels to visible-light range from ultraviolet-light range. Iron compounds are red. Cobalt compounds are blue. Nickel compounds are green. Copper compounds are blue or green. Lead compounds are white. Silver compounds are black.
Nitrogen burns at 800 F to make nitrogen oxides {nitrogen compound}. Cyanuric acid oxidizes nitrogen oxides to carbon dioxide, water, and nitrogen gas.
Ions {phosphate ion}, (PO4)-3 [4 is subscript and -3 is superscript], can have phosphorus and oxygen.
bone
Bone is calcium phosphate, Ca3(PO4)2 [3, 4, and 2 are subscripts]. 20% of skeleton is calcium phosphate. Teeth have calcium phosphate.
energy
Phosphate bonds in adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) store energy.
detergent
Detergents can have phosphates, because phosphate softens water. Many places ban phosphate detergents, because they cause lakes and rivers to have too many algae and other plants, which makes less oxygen in water and kills animal life.
Water {water, molecule} relates to anhydrous, hydrate, efflorescence, deliquescence, hygroscopic, and desiccant.
phases
Water can exist in 13 crystalline phases and five amorphous phases. Water can be high-density amorphous ice at 10 K to 65 K or low-density amorphous ice at 65 K to 125 K. Amorphous ice is in interstellar space. Space amorphous ice can flow with UV light and allows carbon dioxide, carbon monoxide, methanol, and ammonia formation. Cubic ice forms at 135 K to 200 K. Hexagonal ice forms from 200 K to 273 K.
ice surface
Ice has liquid water at surface, several molecules thick, with less structure than solid, because water interacts with air. Ice with impurities has thicker layer. Ice has a liquid surface layer even if it is tens of degrees below freezing. Water-surface-layer charge separation, on ice crystals moving upward and hail falling downward, causes lightning.
Most substances have no adhering water {anhydrous}|.
Solid can absorb water from air and become solution {deliquescence}|.
Chemicals {desiccant}| that can take up water can keep other chemicals dry.
Hydrates can give water to air {efflorescence, water}|.
Substances {hydrate}|, with dissolved ions, can adhere to water.
Compounds can absorb water from air {hygroscopic}|.
Water {hard water}| can have mostly calcium and magnesium ions.
Water {soft water}| can have mostly sodium and potassium ions.
5-Chemistry-Inorganic-Chemical
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Date Modified: 2022.0225